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My recent research efforts are currently focused on clinicopathologic correlations in the fields of gastroenterology and urology. My other efforts are devoted to the design and maintenance of the surgical pathology website surgpathcriteria.stanford.edu

Abstract

Tissue diagnosis of upper tract urothelial carcinoma (UTUC) is limited by variance in tumor sampling by standard ureteroscopic biopsy. Optical imaging technologies can potentially improve UTUC diagnosis, surveillance, and endoscopic treatment. We previously demonstrated in vivo optical biopsy of urothelial carcinoma of the bladder using confocal laser endomicroscopy (CLE). In this study, we evaluated a new 0.85-mm imaging probe in the upper urinary tract and demonstrated feasibility and compatibility with standard ureteroscopes to achieve in vivo optical biopsy of UTUC.Fourteen patients scheduled for ureteroscopy of suspected upper tract lesions or surveillance of UTUC were recruited. After intravenous (IV) administration of fluorescein, CLE was performed using a 0.85-mm-diameter imaging probe inserted through the working channel of standard ureteroscopes. Acquired confocal video sequences were reviewed and analyzed. A mosaicing algorithm was used to compile a series of images into a single larger composite image. Processed CLE images were compared with standard histopathologic analysis.Optical biopsy of the UTUC using CLE was effectively achieved during standard ureteroscopy. There were no adverse events related to IV fluorescein administration or image acquisition. Confocal imaging of UTUC showed characteristic features similar to urothelial carcinoma of the bladder, including papillary structure, fibrovascular stalks, and pleomorphism. Lamina propria in normal areas of the renal pelvis and ureter was also identified.We report an initial feasibility of CLE of UTUC. Pending further clinical investigation, CLE may become a useful adjunct to ureteroscopic biopsy, endoscopic ablation, and surveillance of UTUC.

Abstract

Diminutive (?5?mm) colorectal polyps are common, and overwhelmingly benign. Routinely, after polypectomy, they are examined pathologically to determine the surveillance intervals. Advances in equipment and techniques, such as narrow-band imaging (NBI) colonoscopy, now permit reliable real-time optical diagnosis.We conducted a randomised single-masked study involving three institutions to determine whether optical diagnosis of diminutive colorectal polyps meets clinical practice standards and reduces the need for histopathology. We randomly assigned eligible patients undergoing routine high-definition colonoscopy to optical diagnosis using near focus versus standard view, using computer-generated block sequence. By validated criteria, we rendered an optical diagnosis and a confidence level (high vs low) for all polyps, using NBI. Our primary endpoint was the number of accurate high-confidence optical diagnoses compared with central blinded pathology in the two groups. We analysed data using intention to treat.We enrolled 558 subjects, and randomly assigned 281 to near focus and 277 to standard view optical diagnosis. We detected 1309 predominantly diminutive (74.5%) and neoplastic (60.0%) polyps. Endoscopists were significantly more likely, OR 2.2 (95% CI 1.6 to 3.0, p<0.0001), to make a high-confidence optical diagnosis with near focus (85.1%) than standard (72.6%) view. High-confidence diagnoses had 96.4% and 92.0% negative predictive value, respectively. Of all polyps, 75.3% (95% CI71.3% to 78.9%) had a high-confidence accurate prediction using near focus, compared with 63.1% (95% CI 58.5% to 67.6%) using standard view. Optical versus histopathological diagnosis showed excellent agreement between the surveillance intervals, 93.5% in near focus and 92.2% in standard view. The median diagnosis time was 14?s.Real-time optical diagnosis using NBI colonoscopy may replace the pathology diagnosis for the majority of diminutive colorectal polyps. Using colonoscopy with near focus view increases the confidence level of the optical diagnosis. Optical diagnosis would be a paradigm shift in clinical practice of colonoscopy for colorectal cancer screening.ClinicalTrials.gov Identifier: NCT01288833.

Abstract

The learning curve for optical diagnosis of colorectal polyps with the narrow-band imaging (NBI) is unknown. To forego histological analysis of diminutive polyps diagnosed optically with high confidence, guidelines recommend ??90?% negative predictive value (NPV) and concordance of ??90?% for surveillance intervals predicted optically and histologically. We aimed to study the learning of optical diagnosis for colorectal polyps.We studied five endoscopists as part of a randomized multisite trial comparing near-focus and standard-focus views for optical diagnosis. They trained using a computer-based module, followed by 10 real-time colonoscopies with pathology correlation. Endoscopists then optically diagnosed and resected all the polyps found during 558 consecutive colonoscopies, and diagnoses were compared with pathology. Endoscopists repeated the training module at the study midpoint. NPV and concordance of surveillance intervals for diminutive polyps diagnosed optically with high confidence were measured over time.Endoscopists showed high diagnostic performance, with a nonsignificant trend toward higher NPV in the second half of the study. For the 445 polyps in the standard-view arm, the NPV was 88.0?% (95?%CI 75.7?%?-?95.5?%) in the first half and 95.8?% (88.3?%?-?99.1?%) in the second; P?=?0.7.?Three endoscopists in the first half and four in the second achieved?>?90?% NPV. Concordance of surveillance intervals was identical in the first and second halves at 98.1?% (95?%CI 93.3?%?-?99.8?%).High NPV for the prediction of non-neoplasms with NBI was achieved and maintained in this group of endoscopists who participated in standardized and continued training. Both NPV and surveillance interval agreement indicated high performance in the optical diagnosis of colorectal polyps and exceeded thresholds.

Abstract

Surveillance intervals after colonoscopic resection of serrated polyps are partially predicated on the histology of the polyp(s) removed during the index exam. Histologic discrimination between sessile serrated adenomas/polyps (SSA/P) and hyperplastic polyps is challenging. We devised and tested a simple tool--an envelope--that gastroenterologists can integrate into routine colonoscopy practice to address this problem.In the "modified protocol," immediately after polypectomy each serrated polyp was flattened and enclosed in a paper envelope before being placed in formalin. In the pathology laboratory, each polyp was sectioned after processing. A two-site, prospective, randomized, single-blinded trial was performed to compare this modified protocol with the conventional protocol. Serrated polyps located proximal to the splenic flexure and 5-20 mm in diameter were included. A novel orientation score that measured the number of well-oriented crypts per unit area of polyp (higher orientation score = better orientation) was validated. Orientation score, SSA/P diagnosis rate, and inter-pathologist agreement were measured.A total of 375 polyps were enrolled, of which 264 were identified for analysis. The mean orientation scores in the modified and conventional protocol groups were 3.11 and 1.13, respectively (P < 0.0001). SSA/Ps were diagnosed in 103/135 cases (76.3%) in the modified protocol group vs. 54/129 (41.9%) in the conventional protocol group (P < 0.0001). Inter-pathologist agreement was higher with the modified than the conventional protocol (77.0% vs. 62.8%; P = 0.015).Standard polyp handling techniques may be sub-optimal for interpretation of serrated polyps resected at colonoscopy, and may lead to inadvertent histologic "under-grading" of many lesions. Our intervention improved histopathologic interpretation and increased the SSA/P diagnosis rate.

Abstract

BACKGROUND: Colorectal adenocarcinoma with depth of invasion ?1,000 ?m from the muscularis mucosa and favorable histology is now considered for local resection. We aimed to examine the strength of evidence for this emerging practice. METHODS: We searched Medline, Scopus, and Cochrane (1950-2011), then performed a meta-analysis on the risk of lymph node metastasis in nonpedunculated (sessile and nonpolypoid) T1 colorectal cancers. We included studies with nonpedunculated lesions, actual invasion depth, and pathologic factors of interest. Synchronous, polyposis or secondary cancers, and chemoradiation studies were excluded. Our primary outcome was the risk of LNM. We analyzed using Review Manager; we estimated heterogeneity using Cochran Q ?(2) test and I (2). We generated summary risk ratios using a random effects model, performed sensitivity analyses, and evaluated the quality of evidence using GRADEPro. RESULTS: We identified 209 articles; 5 studies (n = 1213 patients) met the inclusion criteria. The risk of LNM in nonpedunculated ?1,000 ?m is 1.9 % (95 % confidence interval 0.5-4.8 %). The risk for all T1 is 13 % (95 % confidence interval 11.5-15.4 %). Characteristics protective against LNM were ?1,000 ?m invasion, well differentiation, absence of lymphatic and vascular invasion, and absence of tumor budding. We did not detect significant study heterogeneity. The quality of evidence was poor. CONCLUSIONS: Well-differentiated nonpedunculated T1 colorectal cancer invasive into the submucosa ?1,000 ?m, without lymphovascular involvement or tumor budding, has the lowest risk of nodal metastasis. Importantly, the risk was not zero (1.9 %), and the qualitative formal analysis of data was not strong. As such, endoscopic resection alone may be adequate in select patients with submucosal invasive colorectal cancers, but more studies are needed. Overall, the quality of evidence was poor; data were from small retrospective studies from limited geographic regions.

Abstract

Colonic perineuriomas are recently described benign mucosal polyps that are composed of a bland spindle cell proliferation surrounding crypts that often demonstrate hyperplastic/serrated epithelial changes. However, the origin of this unique stromal proliferation is still unclear, and the association with serrated polyps, including sessile serrated adenomas, has not been fully described. We evaluated the pathologic and molecular features of colonic polyps associated with perineurial-like proliferations in 2 retrospective cohorts: (1) a series of 198 consecutive sessile serrated adenomas and (2) 20 colonic polyps diagnosed as a perineurioma irrespective of the presence of serrated colonic crypts. Thirteen of 198 (6.5%) sessile serrated adenomas demonstrated a perineurial-like stromal proliferation, with most (12 of 13, 92%) involving the right (9 cases) and transverse colon (3 cases). In all 13 cases, the perineurial-like proliferation surrounded serrated colonic crypts and typically involved only a small area of the sessile serrated adenoma (average 9% of polyp size; range, 2% to 19%). All 11 polyps evaluated for epithelial membrane antigen (EMA) expression demonstrated stromal EMA staining limited to the perineurial-like proliferation. Twelve of 13 (92%) sessile serrated adenomas with perineurial-like proliferations demonstrated a pV600E BRAF mutation. Of the 20 colonic polyps diagnosed as a perineurioma, 18 (90%) demonstrated serrated crypts intimately associated with the perineurial-like proliferation. In 13 of 18 polyps with associated serrated crypts, all serrated crypts were invested with the perineurial proliferation. In 5 cases, serrated crypts were seen away from the perineurial proliferation. Of these 18 polyps, the majority (16 of 18, 89%) were microvesicular hyperplastic polyps involving the left colon. However, 2 (11%) polyps in the right colon demonstrated histologic features diagnostic of sessile serrated adenoma. All 18 polyps with serrated crypts demonstrated a pV600E BRAF mutation. In contrast, the 2 polyps not associated with serrated crypts were negative for a BRAF mutation. Our results show for the first time that perineurial-like stromal proliferations frequently occur in sessile serrated adenomas. The presence of focal perineurial-like stromal proliferations in sessile serrated adenomas and the common finding of serrated crypts in colonic perineuriomas are likely indicative of an epithelial-stromal interaction, possibly related to some factor elaborated by the serrated epithelium.

Abstract

Brachyury is recognized as a specific marker for notochord-derived tissues and neoplasms, and has become a defining immunohistochemical feature of chordoma. The main differential diagnostic consideration for chordoma is chondrosarcoma, which is known to lack brachyury expression. However, within the spectrum of genitourinary neoplasia, metastatic germ cell tumors and clear cell renal cell carcinoma may also be close morphological mimics of chordoma, particularly given the increasing prevalence of small tissue samples from image-guided biopsies. Although immunoreactivity for brachyury has been reported in a few germ cell tumors, a thorough characterization of staining by specific subtype has not been performed in a large series. Additionally, brachyury expression in clear cell renal cell carcinoma has not been well studied. In this study, immunohistochemical expression with the brachyury antibody was evaluated in 111 germ cell tumors, 30 non-neoplastic and neoplastic (non-germ cell) testicular tissues, and 184 metastatic clear cell renal cell carcinomas using tissue microarray technology. In addition, immunoreactivity for PAX-8 and SALL-4 was evaluated in 12 chordomas on whole section. No nuclear brachyury expression was identified in any of the 101 germ cell tumors within the tissue microarray (including choriocarcinoma (1), embryonal carcinoma (20), intratubular germ cell neoplasia unclassified (2), seminoma (64), spermatocytic seminoma (1), teratoma (5) and yolk sac tumor (8)), in any of the 30 non-neoplastic and neoplastic (non-germ cell) testicular tissues, or in any of the 10 whole-section seminomas. All 184 metastatic clear cell renal cell carcinomas were also non-reactive for brachyury. All 12 chordomas showed strong nuclear immunoreactivity for brachyury, but no expression of SALL-4. In all, 1 of 12 chordoma cases showed patchy, 1+ nuclear immunoreactivity for PAX-8. This study confirms the specificity of brachyury for chordoma in the differential diagnostic distinction from the potential genitourinary mimics, germ cell tumors and metastatic clear cell renal cell carcinoma.

Abstract

In patients with penile squamous cell carcinomas (SCCs), lymphadenectomy can be curative and should be considered in cases deemed high risk for metastatic spread to regional lymph nodes. Management of patients without palpable lymphadenopathy remains controversial. Current guidelines for T1 penile SCCs based on previous studies have suggested that moderately differentiated tumors are at low risk for metastatic disease; however given our experience with such patients we sought to examine whether such tumors were truly observable or should be treated more aggressively.A retrospective chart review of penile cancer cases at three institutions was performed. All slides of patients diagnosed with T1 lesions were rereviewed by our reference pathologists to confirm the original diagnosis and stage. These patients were also reviewed regarding lymphadenectomy results and clinical outcomes.Between 1988 and 2004, a total of 34 cases of SCC of the penis were identified, of which 10 were stage T1. Of these 10 cases, seven had moderately differentiated carcinoma without vascular invasion on pathological evaluation. Metastatic disease was present in one patient at the time of diagnosis and subsequently developed in three of the remaining six patients during follow up. Thus a total of 4 (57%) of the patients developed metastatic disease.Current management protocols place moderately differentiated T1 penile squamous carcinoma without vascular invasion in a low risk category for metastatic disease. As such, expectant management is currently offered as a primary option for these patients. Our experience suggests that patients in this category are in fact at higher risk for metastatic disease, and may be offered early groin dissection in place of expectant management.

Abstract

Adenomatoid tumors of the female and male genital tracts are well characterized as mesothelial in origin, but a detailed histological and immunohistochemical analysis comparing both traditional and newer mesothelial markers across gender and site has not been formally conducted. A variety of morphologic features previously described as characteristic of adenomatoid tumors were evaluated in 44 adenomatoid tumors from the male and female genital tracts. Immunohistochemical analysis with pankeratin (AE1/CAM5.2), WT-1, calretinin, CK5/6, D2-40, and caldesmon was also performed. The extent and intensity of staining were scored semiquantitatively on one representative section per case and mean value for each parameter was calculated. All (n=44) the adenomatoid tumors from both the female and male genital tracts demonstrated a distinctive thread-like bridging strand pattern. Lymphoid aggregates were seen in all 12 adenomatoid tumors of male patients, but in only 4 of 32 (13%) tumors in female patients (P<0.0001). The remaining morphologic features were variably present with no clear sex predilection. Pankeratin, calretinin, and D2-40 reactivity were identified in all female (n=32) and male (n=12) genital tract adenomatoid tumors. Adenomatoid tumors expressed WT-1 in 11/12 (92%) male patients and in 31/32 (97%) female patients. In male patients, reactivity for CK5/6 and caldesmon was found in 1/12 (8%) and 0/12 (0%) adenomatoid tumors (respectively), whereas reactivity in female patients was found in 5/32 (16%) and 1/32 (3%); respectively. Female tumors differ from their male counterparts by the frequent absence of lymphoid aggregates and the presence of a circumscribed margin when occurring in the fallopian tube. Of the putative mesothelial markers evaluated, calretinin, D2-40, and WT-1 show a similar immunoprofile and have a higher sensitivity than CK5/6 and caldesmon in genital tract adenomatoid tumors. However, the presence of additional, often strong expression of WT-1 in normal tissues of the female genital tract limits the utility of WT-1 in this setting.

Abstract

On the basis of recent clinical studies, some urologic oncologists do not offer bladder-sparing therapy for patients diagnosed with micropapillary carcinoma of the urinary bladder, even in the setting superficially invasive disease. Unfortunately, the distinction of invasive micropapillary carcinoma from typical invasive urothelial carcinoma with prominent retraction artifact may be difficult in some cases. In this study, we compared the immunophenotype of invasive micropapillary carcinoma to invasive urothelial carcinoma with retraction artifact using antibodies previously reported as specific for micropapillary carcinoma. Immunohistochemical staining was performed on 24 invasive micropapillary carcinomas of the urinary tract and 24 case controls of invasive urothelial carcinoma with retraction artifact using monoclonal antibodies MUC1, CA125, and Her2Neu. The staining extent and intensity for MUC1 and CA125 were scored on one representative section per case. Immunostaining for Her2Neu was scored based on the 2007 CAP/ASCO guidelines for breast carcinoma. Basal ('reverse-apical') MUC1 staining was identified in 23 of the 24 (96%) invasive micropapillary carcinomas and in 15 of the 24 (63%) invasive urothelial carcinomas with retraction artifact (P=0.0102). Membranous reactivity with CA125 was seen in 8 of the 24 (33%) invasive micropapillary carcinomas and in 3 of the 24 (13%) invasive urothelial carcinomas with retraction artifact (P=0.1681). Positive (3+) membranous Her2Neu staining was present in 6 of 24 (25%) invasive micropapillary carcinomas and in 2 of the 24 (8%) invasive urothelial carcinomas with retraction artifact (P=0.2448). The specificity for invasive micropapillary carcinoma vs invasive urothelial carcinoma with retraction artifact using antibodies MUC1, CA125, and Her2Neu was 37, 87, and 92%, respectively. Invasive micropapillary carcinoma more commonly showed immunoreactivity for MUC1, CA125, and Her2Neu compared to invasive urothelial carcinoma with retraction artifact, but only MUC1 reached statistical significance. The lack of specificity of these evaluated markers for invasive micropapillary carcinoma limits their utility in the distinction from invasive urothelial carcinoma with retraction artifact, especially given the potentially significant therapeutic implications.

Abstract

The transcription factor LMO2 is involved in vascular and hematopoietic development and hematolymphoid neoplasia. We have demonstrated that LMO2 is expressed nearly ubiquitously in native and neoplastic vasculature, including lymphatics. LMO2 reactivity is otherwise virtually absent in nonhematolymphoid tissues except in breast myoepithelium, prostatic basal cells, and secretory phase endometrial glands. Vasculature is LMO2- in adult and fetal heart, brain of older adults, hepatic sinusoids, and hepatocellular carcinoma. LMO2 is uniformly expressed in benign vascular and lymphatic neoplasms and in most malignant vascular neoplasms with the exception of epithelioid vascular neoplasms of pleura and bone. Among nonvascular neoplasms, LMO2 reactivity is present in giant cell tumor of tendon sheath, juvenile xanthogranuloma, a subset of gastrointestinal stromal tumors, small round blue cell tumors, and myoepithelial-derived neoplasms. The restricted expression pattern, nuclear localization, and crisp staining of LMO2 in paraffin blocks make it an attractive candidate for the diagnostic immunohistochemistry laboratory.

Abstract

We investigated the gefitinib, 5-fluorouracil (5-FU), leucovorin and oxaliplatin (IFOX) regimen as first-line therapy in patients with metastatic colorectal cancer.Eligible patients had stage IV colorectal adenocarcinoma, and had not received prior chemotherapy for metastatic disease. Each cycle consisted of 14 days. Cycle 1 consisted of oxaliplatin, leucovorin, and 5-FU (FOLFOX-4). All subsequent cycles consisted of FOLFOX-4 with gefitinib at 500 mg orally daily throughout the 14-day cycle.Forty-five patients were enrolled and were assessable for toxicity. Forty-three patients were assessable for response. Thirty-one of the 43 patients (72%) had either a complete or partial response by the Response Evaluation Criteria in Solid Tumors. Median overall survival was 20.5 months. Median time to progression was 9.3 months. Commonly encountered grade 3 or 4 toxicities included diarrhea in 67% of patients and neutropenia in 60%. Grade 2 acneiform skin rash typical of gefitinib occurred in 60% of patients.IFOX is an active first-line regimen in patients with metastatic colorectal adenocarcinoma, showing higher response rates but also increased toxicities compared with FOLFOX-4 alone in a similar patient population.

Abstract

Colorectal cancer is the second leading cause of cancer death in the United States. Prevention has focused on the detection and removal of polypoid neoplasms. Data are limited on the significance of nonpolypoid colorectal neoplasms (NP-CRNs).To determine the prevalence of NP-CRNs in a veterans hospital population and to characterize their association with colorectal cancer.Cross-sectional study at a veterans hospital in California with 1819 patients undergoing elective colonoscopy from July 2003 to June 2004.Endoscopic appearance, location, size, histology, and depth of invasion of neoplasms.The overall prevalence of NP-CRNs was 9.35% (95% confidence interval [95% CI], 8.05%-10.78%; n = 170). The prevalence of NP-CRNs in the subpopulations for screening, surveillance, and symptoms was 5.84% (95% CI, 4.13%-8.00%; n = 36), 15.44% (95% CI, 12.76%-18.44%; n = 101), and 6.01% (95% CI, 4.17%-8.34%; n = 33), respectively. The overall prevalence of NP-CRNs with in situ or submucosal invasive carcinoma was 0.82% (95% CI, 0.46%-1.36%; n = 15); in the screening population, the prevalence was 0.32% (95% CI, 0.04%-1.17%; n = 2). Overall, NP-CRNs were more likely to contain carcinoma (odds ratio, 9.78; 95% CI, 3.93-24.4) than polypoid lesions, irrespective of the size. The positive size-adjusted association of NP-CRNs with in situ or submucosal invasive carcinoma was also observed in subpopulations for screening (odds ratio, 2.01; 95% CI, 0.27-15.3) and surveillance (odds ratio, 63.7; 95% CI, 9.41-431). The depressed type had the highest risk (33%). Nonpolypoid colorectal neoplasms containing carcinoma were smaller in diameter as compared with the polypoid ones (mean [SD] diameter, 15.9 [10.2] mm vs 19.2 [9.6] mm, respectively). The procedure times did not change appreciably as compared with historical controls.In this group of veteran patients, NP-CRNs were relatively common lesions diagnosed during routine colonoscopy and had a greater association with carcinoma compared with polypoid neoplasms, irrespective of size.

Abstract

Current practice is to perform a completion axillary lymph node dissection (ALND) for breast cancer patients with tumor-involved sentinel lymph nodes (SLNs), although fewer than half will have non-sentinel node (NSLN) metastasis. Our goal was to develop new models to quantify the risk of NSLN metastasis in SLN-positive patients and to compare predictive capabilities to another widely used model.We constructed three models to predict NSLN status: recursive partitioning with receiver operating characteristic curves (RP-ROC), boosted Classification and Regression Trees (CART), and multivariate logistic regression (MLR) informed by CART. Data were compiled from a multicenter Northern California and Oregon database of 784 patients who prospectively underwent SLN biopsy and completion ALND. We compared the predictive abilities of our best model and the Memorial Sloan-Kettering Breast Cancer Nomogram (Nomogram) in our dataset and an independent dataset from Northwestern University.285 patients had positive SLNs, of which 213 had known angiolymphatic invasion status and 171 had complete pathologic data including hormone receptor status. 264 (93%) patients had limited SLN disease (micrometastasis, 70%, or isolated tumor cells, 23%). 101 (35%) of all SLN-positive patients had tumor-involved NSLNs. Three variables (tumor size, angiolymphatic invasion, and SLN metastasis size) predicted risk in all our models. RP-ROC and boosted CART stratified patients into four risk levels. MLR informed by CART was most accurate. Using two composite predictors calculated from three variables, MLR informed by CART was more accurate than the Nomogram computed using eight predictors. In our dataset, area under ROC curve (AUC) was 0.83/0.85 for MLR (n = 213/n = 171) and 0.77 for Nomogram (n = 171). When applied to an independent dataset (n = 77), AUC was 0.74 for our model and 0.62 for Nomogram. The composite predictors in our model were the product of angiolymphatic invasion and size of SLN metastasis, and the product of tumor size and square of SLN metastasis size.We present a new model developed from a community-based SLN database that uses only three rather than eight variables to achieve higher accuracy than the Nomogram for predicting NSLN status in two different datasets.

Abstract

Odontogenic neoplasms have some morphologic overlap with salivary gland neoplasms, many of which show myoepithelial differentiation. In the 1980s, an ultrastructural study identified a population of myoepithelial-like cells in calcifying epithelial odontogenic tumor. Myoepithelial derived tumors have since been shown to have distinct immunohistochemical profiles.We examined a series of odontogenic neoplasms, including 11 ameloblastomas, four calcifying epithelial odontogenic tumors, five glandular odontogenic cysts (GOCs), and five keratocystic odontogenic tumors with a panel of myoepithelial-associated immunohistochemical stains. We also assessed representative control examples of oral mucosa, odontogenic rests, and dentigerous cysts.All of the neoplastic and non-neoplastic oral epithelium-derived entities share a p63-positive, high molecular weight cytokeratin (CK5/6)-positive immunophenotype. Calponin reactivity was at least focally present in two of four calcifying epithelial odontogenic tumors, three of five GOCs, and 10 of 11 ameloblastomas; the sole completely non-reactive ameloblastoma represents a lung metastasis. One case of calcifying epithelial odontogenic tumor was focally positive for glial fibrillary acidic protein. However, other more definitive markers of myoepithelial differentiation, including S-100 and smooth muscle actin, were negative. Two of three calcifying epithelial odontogenic tumors and five of five GOCs were also positive for a low molecular weight cytokeratin (CK7).Ameloblastomas, GOCs, and calcifying epithelial odontogenic tumors show a distinctive immunophenotype which overlaps with that of myoepithelial-derived salivary gland neoplasms but does not provide definitive support for myoepithelial differentiation.

Abstract

In 1998 the Veterans Administration mandated an externally monitored targeted colon cancer screening rate that was expected to result in earlier cancer detection and improved patient survival. The effectiveness of the protocol was evaluated in a retrospective case series at a tertiary care Veterans Administration Hospital that included all patients with the diagnosis of colon cancer between 1991 and 2003.Tumor stage, tumor location, and patient survival data were recorded and compared to National Cancer Data Base (NCDB) benchmarks.The study facility had a greater percentage of early cancers and fewer later stage cancers than the NCDB benchmark. Overall survival was better for the VA cohort compared to NCDB (all-cause 5-year survival: VA, 0.72; NCDB, 0.47. p < or = .001).The VA facility had a significantly greater percentage of early cancers and fewer stage III or IV cancers compared to a national benchmark and significantly improved survival compared to the national benchmark.

Abstract

Extragonadal germ cell tumors (GCTs) are relatively uncommon, but represent 1% to 5% of all GCTs. Their morphology varies widely and includes mature teratoma, immature teratoma, seminoma, yolk sac tumor, embryonal carcinoma, choriocarcinoma, and mixed GCTs. Noncentral nervous system extragonadal GCTs are found in a variety of anatomic locations, but most commonly affect the mediastinum and sacrococcygeal region. Predicting behavior in these tumors can be confusing because it is based on a combination of varying factors including patient age, histologic subtype, anatomic site, and clinical stage. This review attempts to dissect these issues by separating the discussion into 3 age groups: neonatal (congenital), children (prepubertal), and adult (postpubertal). Within each individual age group, we cover the significance of anatomic site, morphology, and staging parameters. In addition, we discuss the spectrum of associated secondary malignancies and their impact on patient outcome. Finally, we provide a detailed survey of differential diagnostic considerations grouped by anatomic site.

Abstract

The Veterans Administration hospitals underwent an institutional directive in 1998 to meet a colorectal cancer screening (CRCS) standard. This intervention should result in an increase in the hospital's screening rate and percentage of early-stage rectal cancers diagnosed.A retrospective review, from 1991 to 2002, of our institution's pathology and cancer registry databases for rectal cancers. CRCS data were obtained from the Veterans Administration Prevention Disease Index. Cancer stage at diagnosis was compared before and after the directive and was compared with the National Cancer Data Base and the Surveillance, Epidemiology, and End Results data.The rate of CRCS was 55% in 1998 and increased to 75% in 2003. During the 11 years studied, a total of 147 rectal cancers were diagnosed. After the Veterans Administration directive, there was a significant increase in stage 0 cancers (P < .02) and an overall migration to earlier-stage cancers. Our Veterans Administration hospital had a significantly greater percentage of stage 0 cancers both before (P < .007) and after the directive (P < .00) and had fewer stage 3 cancers after the directive (P < .03) compared with National Cancer Data Base data. Compared with Surveillance, Epidemiology, and End Results data, the Palo Alto Veterans Affairs Health Care System had more local disease (P < .03) and less regional disease (P < .006).These data suggest that a monitored institutional directive may significantly increase early detection of rectal cancers. This should result in a greater survival rate and lower local recurrence rate, because survival is predicated on stage at presentation. This may serve as a model for other health-care systems.

Abstract

The diagnosis of malignant melanoma remains one of the most difficult to render in surgical pathology, partially because of its extreme histologic variability. Limits in the sensitivity and/or specificity of the currently available melanocytic markers such as anti-S100, HMB45, and anti-MelanA further complicate this problem. Previous work has demonstrated that the B-cell proliferation/differentiation marker MUM1/IRF4 is detected in malignant melanoma and hematolymphoid malignancies, but not in any other neoplasm tested (including colonic, lung, breast, and ovarian carcinomas). In the current study, we have examined MUM1 protein expression in 61 melanocytic lesions and compared the diagnostic usefulness of this marker with that of anti-S100, HMB45, and anti-MelanA. The results indicate that MUM1 is positive in 33/36 (92%) cases of melanoma (21/22 [95%] conventional primary melanomas and 12/14 [86%] metastatic melanomas). In comparison, positivity was seen with anti-S100 in 36/36 cases (100%, 22 primary and 14 metastatic), HMB45 in 28 cases (78%, 17 primary and 11 metastatic), and anti-MelanA in 27 cases (75%, 19 primary and 8 metastatic). Although negative in schwannomas, neurofibromas, and malignant peripheral nerve sheath tumors, MUM1 is detected in only one in eight cases of spindle cell and desmoplastic melanomas. With the exception of desmoplastic and spindle cell melanomas, MUM1 appears to be a sensitive and specific immunohistochemical stain for melanocytic lesions and may prove to be a useful addition to the current panel of melanoma markers.

Abstract

A well-characterized positive marker for hepatocellular differentiation would be a useful tool for the diagnosis of hepatocellular carcinoma (HCC). The recently commercially available Hep Par 1 antibody (clone OCH1E5.2.10) has been reported to be a sensitive marker for HCC in paraffin embedded sections. Of non-hepatocellular tumors, occasional carcinomas have been reported to stain, most frequently gastric adenocarcinomas. This study further evaluated the staining of this antibody on a large number of neoplasms using tissue microarray technology as well as conventional tissue sections. Six hundred seventy-six tumors, including 19 cases of HCC, were tested. Eighteen of 19 cases of HCC were positive, 3 showing <5% staining. Two cases negative on the array showed focal staining when whole tissue sections from the same tumors were used. 16 of 34 cases of gastric carcinomas gave positive reactions, 4 of these showed less than 5% staining. Staining of gastric carcinomas was not limited to signet ring-type carcinomas or to areas of hepatoid differentiation. Only 1 of 11 cases of cholangiocarcinoma showed focal staining. We also noted several other tumors to stain occasionally, including adrenal cortical carcinoma (3/13), yolk sac tumor (2/9), colonic adenocarcinoma (8/106), lung carcinoma (3/52), ovarian carcinoma (5/48), and endocervical adenocarcinoma (1/5). We did not observe staining in pancreatic carcinoma (11), renal cell carcinoma (36), breast carcinoma (85), melanoma (25), or mesothelioma (5). This study supports Hep Par 1 as a useful marker in the differential diagnosis of HCC, but with significant limitations. Cautious use of this antibody in a panel with other positive (alpha fetoprotein, CD10, polyclonal carcinoembryonic antigen) and negative (epithelial membrane antigen, monoclonal carcinoembryonic antigen, CD15) markers of hepatocellular differentiation may aid in the accurate diagnosis of HCC.

Abstract

We report the unusual case of a 78-year-old man who presented with obstructive bowel symptoms and a 2.5-cm presacral mass. The mass was excised and found on pathologic examination to be ectopic prostate tissue complete with a muscular stroma. Review of the literature revealed a number of case reports describing variably sized fragments of ectopic prostate tissue involving a variety of organs, including spleen, uterine cervix, bowel wall, pericolic fat, anal submucosa, seminal vesicle, testis, and urinary bladder. However, to our knowledge, this case is unique in that it presented as a relatively large, isolated presacral mass causing functional bowel impairment. The ectopic location can be related to the normal embryonic development of the prostate, rectum, and bladder.

Abstract

Merkel cell carcinoma is an aggressive cutaneous neoplasm with neuroendocrine differentiation that carries a poor prognosis. Its homogeneous morphology is easily confused with lymphoma, leukemia, metastatic small cell carcinoma, and poorly differentiated cutaneous malignancies. Histopathologic diagnosis frequently requires support by immunohistochemistry. The authors investigated cytokeratins (CKs) 5/6, 7, 17, and 20 staining in paraffin sections of 26 Merkel cell carcinomas to expand the knowledge of the CK staining profile of this entity. Reactivity with anti-CK 20 was demonstrated in 23 of 26 Merkel cell carcinomas (88%). All three CK 20-negative tumors showed punctate staining with anti-keratin CAM5.2. Six of 26 tumors (23%) were positive for CK 7, a finding not previously reported. The staining patterns for both CKs 20 and 7 ranged from punctate (perinuclear) to localized (confined to half of the cytoplasm) to diffuse. Punctate CK 20 staining was seen in 17 of 26 cases but was the predominant pattern in only 10 cases. Antibodies to CKs 5/6 and 17 were each negative in the 13 cases for which these stains were performed. Both the positive and negative elements of the CK profile of this distinctive neoplasm provide additional useful diagnostic information for the differential diagnosis between Merkel cell carcinoma and other carcinomas that may simulate it. The authors note that the classically described perinuclear dotlike keratin staining pattern is not universally seen with CK 20 and that CK 7 staining may be seen in a subset of Merkel cell carcinomas.

Abstract

Spindle cell lipoma demonstrates a distinctive histologic appearance and characteristic clinical presentation. We recently observed two cases of solitary subcutaneous neoplasm of the foot with histologic features of spindle cell lipoma that in one case includes a minor component of the overlapping tumor, pleomorphic lipoma. Because the foot is an unusual location for these neoplasms, immunoperoxidase and cytogenetic studies were performed. In both cases, staining was strongly positive for CD34 and negative for smooth muscle actin. Cytogenetic studies from the tumor with a pleomorphic component revealed features consistent with a lipomatous neoplasm, but are otherwise diagnostically nonspecific. An analysis of the literature reveals that although CD34 immunoreactivity is characteristic of spindle cell lipoma and helps exclude nonlipomatous neoplasms, it does not clearly eliminate other well-differentiated lipomatous tumors. Accordingly, without the aid of classic tumor location, the diagnosis of the spindle cell/pleomorphic lipoma group relies primarily on histologic features, with supportive but not definitive information provided by immunoperoxidase and cytogenetic studies. Obscuring this issue, however, are the imprecise histologic distinction between these tumors and those of the atypical lipoma/atypical lipomatous tumor/ well-differentiated liposarcoma group and the nomenclature controversy that surrounds the latter group of neoplasms. Despite these obstacles, both groups of well-differentiated lipomatous tumors are clinically benign when subcutaneously located.

Abstract

The authors studied a series of 21 cases of pulmonary sclerosing hemangioma (SH) to address conflicting and unconfirmed reports of immunohistologic evidence of differentiation that have been made in the literature. They found the lesional cells of SH to be epithelial membrane antigen (EMA) positive (21 of 21 cases), to be keratin positive only infrequently and focally (six of 21), and to be nonreactive for carcinoembryonic antigen, S-100, smooth muscle actin, and CD34. Faint nuclear staining was seen for estrogen receptors, whereas progesterone receptors were expressed strongly in 17 cases. Neuroendocrine markers (chromogranin A, adrenocorticotrophic hormone, human growth hormone, and calcitonin) were negative uniformly on the lesional cells except for one case in which rare chromogranin-positive cells were present and another case in which rare human growth hormone-positive cells were seen. In contrast to the general EMA-positive, keratin-negative phenotype of the lesional cells, the cells lining the papillae or air spaces within the SH were typically positive for both markers. The following other lesions were identified in the cases studied: carcinoid tumorlets (n = 2), a neuroendocrine body (n = 1), and multiple meningothelial-like nodules (n = 1). All were clearly separable from the SH on morphologic grounds. The authors interpreted these to be chance occurrences of unrelated lesions. Recognition of the phenotype of SH as EMA positive, keratin weak to negative, and negative for S-100, smooth muscle actin, and neuroendocrine markers is notable in its differential diagnosis from other lesions. This phenotype does not suggest a precise lineage or type of differentiation for SH.

Abstract

CD34 is a heavily glycosylated transmembrane protein of approximately 110 kd whose function is essentially uncharacterized. First identified in a myeloid leukemia cell line, immunohistological reactivity with anti-CD34 antibodies is also encountered in a histologically diverse subset of nonhematolymphoid neoplasms including angiosarcoma, solitary fibrous tumors, epithelioid sarcomas, spindle cell lipomas, dermatofibrosarcoma protuberans, and myofibroblastomas. Immunohistological reactivity for CD34 in hematopoietic stem cells and endothelial cells has been shown to correspond to the expression of the CD34 protein. With the exception of gastrointestinal stromal tumors, CD34 protein expression has not been investigated in other CD34 immunohistologically reactive nonhematolymphoid neoplasms. We undertook this study to examine whether the observed reactivity for anti-CD34 antibodies in apparently unrelated tumors is due to the expression of the same protein or whether shared epitopes elaborated by other proteins could account for this reactivity. Immunoblot analyses with anti-CD34 antibodies of six different CD34 immunohistologically reactive lesions show the same approximately 110-kd molecular weight protein. In addition, two cases of dermatofibrosarcoma protuberans show double bands at approximately 110 kd. Laser-capture microdissection of CD34 immunohistologically reactive epithelioid sarcoma and nonreactive epidermal cells illustrates that this reactivity is specific to tumor cells. These results show that the observed immunohistological reactivity with anti-CD34 antibodies is due to the expression of the CD34 protein and not to shared epitopes on unrelated proteins.

Abstract

Systemic mast cell disease is characterized by an abnormal infiltration of mast cells involving several parenchymal organs and the bone marrow. Its spectrum of clinical and histologic presentation is highly variable and is not necessarily correlated with prognosis. Mast cell disorders presenting as atypical infiltrates in the bone marrow may simulate or be associated with other hematolymphoid malignancies, from which they must be distinguished. The paucity of reliable histochemical and immunohistochemical markers for the detection of mast cells in paraffin sections further confounds this diagnosis. The authors have employed immunohistochemistry for the C-KIT encoded tyrosine kinase receptor protein, CD117, for detection of mast cells on paraffin sections of 89 bone marrow specimens including systemic mast cell disease and other disorders. CD117 staining was found in all cases of mast cell disorders (seven of seven), and in one case of chronic myelogenous leukemia in blast crisis. None of the other myeloid disorders tested (0 of 16), or any of the cases of Hodgkin's disease (0 of 12), B-cell lymphomas (0 of 32), T-cell lymphomas (0 of 3), or histiocytic proliferations (0 of 3) showed staining for CD117. CD117 expression is effective in the separation of mast cell disease from disorders that may simulate it histologically.

Abstract

A case of basal cell carcinoma with giant cells of the central epithelial and surrounding stromal components is presented. The lesion was an 8-mm dome-shaped papule on the ear of a 66-year-old man. The giant cells of the epithelial component shared the immunophenotype of the more typical cells of the basal cell carcinoma (keratin, smooth muscle actin, and bcl-2 positive), whereas the stromal giant cells were positive only for bcl-2. This case represents a peculiar variant of pleomorphic basal cell carcinoma, the significance of which is unknown.

Abstract

Uterine mesenchymal neoplasms with sex-cord-like elements are designated as endometrial stromal tumor with sex-cord-like elements (ESTSCLE) or uterine tumor resembling ovarian sex-cord tumor (UTROSCT), depending on the extent of sex-cord-like differentiation. Occasionally, sex-cord elements similar to those in ESTSCLE and UTROSCT occur in uterine adenosarcomas. To determine whether the sex-cord-like elements in these tumors show immunohistological evidence of sex-cord differentiation, we studied a series of uterine neoplasms for expression of inhibin, a peptide hormone expressed by normal ovarian granulosa cells and ovarian sex-cord neoplasms, and CD99, a protein also expressed by granulosa cells, Sertoli cells, and some ovarian sex-cord tumors. Thirty uterine mesenchymal neoplasms (five epithelioid or plexiform smooth muscle tumors, three endometrial stromal tumors, two mixed endometrial stromal and smooth muscle tumors, 10 ESTSCLE, five UTROSCT, and five miscellaneous stromal processes) and five epithelial neoplasms were evaluated for expression of CD99 (clone 12E7) and inhibin (clone R1) in formalin-fixed, paraffin-embedded tissue. Three of 10 (30%) ESTSCLE and five of five (100%) UTROSCT were inhibin and CD99 immunoreactive. Inhibin staining was confined to the areas with sex-cord-like differentiation, and staining was generally much stronger and more extensive in areas featuring prominent foam cells. There were no differences in the degree or intensity of staining for inhibin in premenopausal and postmenopausal women. CD99 expression tended to correlate with inhibin and was typically confined to similar cell types in the individual neoplasms. Weak CD99 immunoreactivity was seen in one additional epithelioid smooth muscle tumor, whereas all other mesenchymal and epithelial neoplasms studied for inhibin and CD99 were negative. These results provide further immunohistological support for true sex-cord differentiation within uterine mesenchymal proliferations and suggest that the degree of sex-cord differentiation may correlate with the expression of these markers.

Intraepidermal cytokeratin 7 expression is not restricted to Paget cells but is also seen in Toker cells and Merkel cellsAMERICAN JOURNAL OF SURGICAL PATHOLOGYLundquist, K., Kohler, S., Rouse, R. V.1999; 23 (2): 212-219

Abstract

Histologically, extramammary Paget's disease and mammary Paget's disease (MPD) are characterized by large atypical cells distributed throughout the epidermis. Although classic examples of these disorders are easily diagnosed on morphologic grounds, some cases may cause differential diagnostic problems. Immunohistology with a wide variety of antibodies has been used as an aid for the identification of Paget cells, for their distinction from other entities, and for investigation of the origin or nature of the disorder. Recently, cytokeratin 7 has been proposed as a specific and 100% sensitive marker for Paget's disease. We studied 22 cases of mammary Paget's disease and 22 cases of extramammary Paget's disease with and without an underlying malignancy for their reactivity with monoclonal antibodies to cytokeratin 7 (CK7) and cytokeratin 20 (CK20). Our studies show that anti-CK7 is an effective but not 100% sensitive marker for Paget cells, staining 21 of 22 cases of mammary Paget's disease and 19 of 22 cases of extramammary Paget's disease, whereas CK20 stained 0 of 17 cases of mammary Paget's disease and 6 of 19 cases of extramammary Paget's disease. We also demonstrate that CK7, but not CK20, highlights intraepidermal clear cells with bland nuclear features (Toker cells) that have been reported in 11% of normal nipples. By using CK7 as a marker, however, we were able to identify Toker cells in most of the nipples we studied: 8 of 15 nipples from mastectomy patients without Paget's disease, and 15 of 18 autopsy cases (both male and female) with normal breasts and nipples. It also permitted us to perform more extensive phenotyping on them, showing that Toker cells share similar antigens with Paget cells and with cells lining the underlying normal lactiferous ducts. In 7 of 15 cases containing CK20-positive Merkel cells, CK7 was also seen to stain Merkel cells. In infrequent cases, Toker cells or Merkel cells may be so numerous focally that a CK7 stain may raise the possibility of involvement of the nipple by Paget's disease. An awareness of the CK7 reactivity of Toker cells and Merkel cells as well as attention to the cytologic features of the case should avoid this problem.

Abstract

In addition to Paget's disease, a heterogeneous group of processes with diverse histogeneses can give rise to intraepidermal pagetoid cells. These diseases share as their common denominator the presence of discrete non-Malpighian or abnormal Malpighian cells occurring singly or in nests within the epidermis. Either Pagetoid cells can represent the only histologic change, as in pagetoid squamous cell carcinoma in situ or superficial spreading malignant melanoma in situ, or they can be an expression of an associated dermal or internal malignancy, as in sebaceous carcinoma or breast carcinoma. The histologic appearance of the pagetoid cells in these diverse disorders can be quite similar, rendering the differential diagnosis difficult. A review of the entities that enter into the differential diagnosis of intraepidermal pagetoid cells is presented, emphasizing their distinguishing histologic and immunophenotypic features and differential diagnosis.

Abstract

Inhibins are peptide hormones that participate in the regulation of the pituitary-gonadal feedback system and are selectively expressed by cells of sex cord-stromal derivation. To determine the efficacy of this marker for distinguishing granulosa cell tumors, 134 primary and metastatic lesions of the ovary were evaluated for expression of the alpha-subunit of inhibin in routinely processed formalin-fixed, paraffin-embedded tissue. A variety of sex cord-stromal tumors (SCST), including 35 adult and juvenile granulosa cell tumors, 14 fibroma-thecomas, and 18 other sex cord-stromal proliferations, were studied. In addition, 33 surface epithelial neoplasms, 12 germ cell tumors, 11 metastases, and 11 miscellaneous ovarian neoplastic proliferations were evaluated. Among the non-granulosa cell neoplasms, special emphasis was placed on primary neoplasms and metastases that histologically simulated granulosa cell tumors. Thirty-three of 35 (94%) granulosa cell tumors were immunoreactive compared with 2 of 12 (17%) primary ovarian endometrioid tumors, one of nine (11%) primary ovarian transitional cell (Brenner) proliferations, and 3 of 17 (18%) other primary and metastatic poorly differentiated (undifferentiated) carcinomas. In 31 of the 35 granulosa cell tumors, inhibin staining was of moderate to strong intensity or was present in at least half of the constituent cells, whereas only 2 of 33 primary surface epithelial neoplasms fulfilled the same criteria, showing weak staining of 70% to 80% of the cells. In contrast, 10 of 14 (71%) ovarian fibroma-thecomas and 17 of 18 (94%) other sex cord-stromal proliferations were positive for inhibin. Nonneoplastic luteinized stromal cells stained for inhibin in 29 of 85 cases in which they could be evaluated. The results of this study show that although it is not completely specific and cannot reliably distinguish granulosa cell tumors from fibroma-thecomas or other ovarian sex cord-stromal proliferations, inhibin can be used to help distinguish sex cord-stromal neoplasms from most primary and metastatic non-SCST. Caution should be exercised in the interpretation of inhibin-positive cells, because a wide variety of primary and metastatic ovarian tumors may contain significant numbers of positively staining luteinized cells.

Abstract

We present a case of transient Menetrier's disease (MD) that was associated with chylous ascites. Using immunohistochemistry, we studied the expression of transforming growth factor alpha in this patient's gastric mucosa biopsy over time; a growth factor that has previously been shown to play an active role in the pathogenesis of MD. Excessive expression and altered localization of transforming growth factor alpha was observed while the patient had active disease with return to the normal pattern after resolution of the disease. This case is the first one reported of transient MD associated with chylous ascites; it lends further credible evidence to the concept that altered transforming growth factor alpha expression may play an important role in the pathogenesis of MD.

Abstract

The clinical, histologic, and immunohistologic features of 22 desmoplastic melanomas (DMM), 10 mixed desmoplastic and spindle-cell melanomas (DMM/SMM), and two cellular spindle-cell melanomas (SMM) were studied. Patients ranged in age from 35 to 91 years (mean, 67) and included 23 men and 11 women. Seventeen cases occurred in sun-damaged skin of the head and neck. 11 were on the extremities, and six on the trunk. Except for two cases, all were Clark's level IV or V. Twenty-two (65%) cases were associated with a recognizable overlying pigmented lesion. Thirty of 32 (94%) DMM and DMM/SMM were clearly positive for S100. S100 staining was limited to < 5% of the spindle cells in two DMM/SMM. All DMM were negative when stained with HMB45. Three DMM/ SMM were immunoreactive with HMB45, as were both SMM. CD68 staining was limited to < 5% of the spindle cells in two of 32 DMM and DMM/SMM and 20% of the cells in one of two SMM. Nine (32%) DMM and DMM/SMM contained significant numbers of spindle cells immunoreactive for SMA but not desmin. In five cases, the number of actin-positive spindle cells. Two color stains for SMA and S100 demonstrated that these smooth-muscle actin positive cells constituted a separate spindle-cell population, consistent with reactive myofibroblasts. This study indicates that the immunohistologic features of desmoplastic melanoma differ from those of conventional melanoma. If a problematic spindle-cell skin lesion is a suspected melanocytic process, HMB45 is unlikely to provide confirmatory (or exclusionary) evidence for the diagnosis of DMM. Similarly, because of the variability in S100 expression in this neoplasm, the absence of S100 staining should not be relied on too heavily to exclude DMM if the clinical and histologic features favor that diagnosis. Caution should be exercised in the interpretation of numerous actin-positive spindle cells in isolation of additional confirmatory or exclusionary data as desmoplastic melanomas may contain significant numbers of these cells.

Abstract

Walthard cell nests, the Brenner tumor (benign, proliferating, low malignant potential, and malignant), and primary ovarian transitional cell carcinoma are considered to be primary female genital tract proliferations of transitional-type (urothelial) epithelium on conventional light microscopic grounds. In order to further investigate the similarities (or dissimilarities) of proliferations of female genital tract transitional epithelium and urothelium, we compared transitional cell proliferations (TCPs) of the female genital tract (n = 25) and urinary bladder (n = 15) using antibodies to carcinoembryonic antigen (CEA; clone 0062), carbohydrate determinant 19-9 (CA19-9; clone 1116-NS-19-9), cytokeratin 7 (CK-7; clone OV-TL 12/30), and cytokeratin 20 (CK-20; clone Ks 20.8), four monoclonal antibodies that have been shown to stain transitional cell urothelial proliferations. Both groups of tumors exhibited significant staining for CEA, CA19-9, and CK-7, and the difference in numbers of cases staining was not significant. CA19-9 was present in 15 of 25 female genital tract TCPs as compared with 12 of 15 bladder TCPs; CEA was present in 17 of 25 female genital tract TCPs and nine of 15 comparable bladder TCPs. CK-7 was present in all cases studied with the exception of one Walthard cell nest and a malignant Brenner tumor that was not immunoreactive with the other antibodies tested. In contrast, 13 of 15 bladder TCPs were CK-20 positive, whereas only one of 25 female genital tract TCPs was positive (< 5% of cells). Walthard cell nests and benign Brenner tumors were more likely to be CA19-9 positive than were Brenner tumors of low malignant potential, malignant Brenner tumors, and primary transitional cell carcinoma of the ovary. We conclude that despite their apparent morphologic and immunologic similarity to TCPs of the urinary bladder (particularly at the histologically low-grade end of the transitional cells spectrum), Walthard cell nests and ovarian Brenner tumors constitute an immunophenotypically distinct form of TCP.

Abstract

It can be extremely difficult in some cases to distinguish atypical polypoid adenomyomas (APAs) from invasive adenocarcinoma in an endometrial curettage or biopsy specimen. In order to determine if immunophenotypic features can be exploited to differentiate between these two entities in problematic cases, a series of APAs and myoinvasive well-differentiated endometrial carcinomas (WDCAs) were studied with a panel of standard immunohistochemical markers. All 23 APAs had stromal smooth muscle actin (SMA) reactivity, 12 of 23 had variable degrees of stromal desmin reactivity, and nine of 22 had CD34-positive stromal cells. All epithelial components of the APAs were cytokeratin (AE1 and CAM5.2) positive, whereas 22 of 23 were positive for estrogen receptor (ER) and progesterone receptor (PR). Among the 10 myoinvasive WDCAs, all contained at least some SMA-positive stromal cells, seven of 10 desmin-positive stromal cells, and four of eight CD34-positive stromal cells. All carcinomas studied demonstrated CAM5.2 and PR-positive epithelia; nine of 10 were ER positive. We conclude that the immunophenotype of APAs does not differ significantly from well-differentiated endometrial adenocarcinoma and that immunophenotyping is of little value in distinguishing APA from carcinoma. Because the stroma in APAs histologically and immunophenotypically more closely resembles a hybrid myofibromatous stroma, we prefer to refer to these lesions with the modified designation "atypical polypoid adenomyofibroma," although "APA" may be retained for clinical use.

Abstract

We present the clinicopathological and immunohistochemical features of 55 atypical polypoid adenomyofibromas, a definitional expansion of an entity previously reported as "atypical polypoid adenomyoma" (APA) of the uterus. Patients ranged in age from 25 to 73 (mean, 39.9) years. All but two of the patients were premenopausal, and 14 were undergoing evaluation for infertility. Histologically, the lesions featured a biphasic proliferation of architecturally complex and cytologically atypical endometrial glands within a myofibromatous stroma. The histologic pattern ranged from widely separated and loosely clustered irregular but branched glands embedded in broad zones of cellular myofibromatous stroma to those possessing crowded, markedly complex, branching glands separated by sparse intersecting fascicles of fibromuscular tissue. The stroma in all cases was actin or desmin positive or both. Morular/squamous metaplasia was present in all but two cases and florid in most. All cases exhibited architecturally complex glands, and in 25 cases the architectural complexity was indistinguishable from that of well-differentiated endometrial adenocarcinoma, as we have defined it; that is, they had a high architectural index. Twenty-nine patients were initially treated with polypectomy or curettage followed by hormonal therapy; persistent or recurrent APA developed in 45% of the patients in this group (33% with low architectural index vs. 60% with high architectural index). Five patients had successful pregnancies despite persistent disease. Superficial myoinvasion was identified in the hysterectomy specimen in two of 12 APAs with a high architectural index but not in 21 APAs with a low architectural index. All patients are alive and well 1 to 112 months after diagnosis (mean, 25.2 months). On the basis of this study, we propose that APAs with markedly complex glands (high architectural index) be designated "atypical polypoid adenomyofibromas of low malignant potential" (APA-LMP) to emphasize the potential risk for myometrial invasion. A treatment program featuring local excision accompanied by close follow-up is warranted for APA despite the presence of recurrent or persistent disease. Patients with APA-LMP may also, in selected cases, be managed with less than hysterectomy, although (as with the usual well-differentiated carcinoma) there is a small but definite risk associated with this approach.

Abstract

An 81-year-old man with a 3-year history of dysphagia underwent endoscopic resection of a 1-cm-diameter distal esophageal mass. Examination revealed a submucosal neoplasm with a circumscribed growth pattern composed of tubules, cysts, and papillae in association with a marked interstitial lymphoid infiltrate. The cyst lumens and papillae were lined by two to six layers of cytologically bland cuboidal to columnar cells with rare mitotic figures. The basal layer of cells was uniformly positive for smooth-muscle actin. Mucin-positive intracytoplasmic lumens were focally present, but cytoplasmic mucin was not seen. There was no evidence of Barrett's metaplastic epithelium. These features are similar to those in two, possibly three, previously reported cases of esophageal adenomas and bear a resemblance to sialadenoma papilliferum, a rare neoplasm of the minor salivary glands. Their clinicopathologic and immunohistologic features suggest that these neoplasms derive from the submucosal gland ducts. Comparison with the previously reported cases indicates that although the proportions of the various components (tubules, cysts, and papillae) may vary, all cases appear to pursue a slowly growing, clinically indolent course with no evidence of recurrence after complete resection.

Abstract

Before the development of thymic lymphoma, AKR mice undergo a striking lymphoid hyperplasia of the thymic medulla. We have previously shown that there is a marked increase in traffic of B and T lymphocytes from the periphery into the preneoplastic, hyperplastic thymuses of these mice, in contrast to the scant traffic of such cells to normal thymuses. The traffic of lymphocytes to lymph nodes and Peyer's patches is controlled in part by the interaction of lymphocyte adhesion molecules called homing receptors with their tissue-selective endothelial ligands known as vascular addressins. We have investigated the roles of homing receptors and vascular addressins in the traffic of lymphocytes to the AKR hyperplastic thymus. We demonstrate that development of hyperplasia is accompanied by an increase in the number of thymic medullary blood vessels with high endothelial venule morphology and expression of the peripheral node addressin (PNAd) and the mucosal addressin (MAdCAM-1). In vitro and in vivo functional assays show that the addressin/homing receptor pairs PNAd/L-selectin and MAdCAM-1/alpha 4 beta 7 are involved in lymphocyte traffic to the hyperplastic thymus. These results indicate that molecular adhesion mechanisms involved in tissue-selective migration of lymphocytes to peripheral lymph node and to mucosal lymphoid tissues play a role in the recruitment of B and T lymphocytes to the AKR thymus and thus in the pathogenesis of thymic hyperplasia.

Abstract

The group A rotaviruses are significant human and veterinary pathogens in terms of morbidity, mortality, and economic loss. Despite its importance, an effective vaccine remains elusive due at least in part to our incomplete understanding of rotavirus immunity and protection. Both large and small animal model systems have been established to address these issues. One significant drawback of these models is the lack of well-characterized wild-type homologous viruses and their cell culture-adapted variants. We have characterized four strains of murine rotaviruses, EC, EHP, EL, and EW, in the infant and adult mouse model using wild-type isolates and cell culture-adapted variants of each strain. Wild-type murine rotaviruses appear to be equally infectious in infant and adult mice in terms of the intensity and duration of virus shedding following primary infection. Spread of infection to naive cagemates is seen in both age groups. Clearance of shedding following primary infection appears to correlate with the development of virus-specific intestinal IgA. Protective immunity is developed in both infant and adult mice following oral infection as demonstrated by a lack of shedding after subsequent wild-type virus challenge. Cell culture-adapted murine rotaviruses appear to be highly attenuated when administered to naive animals and do not spread efficiently to nonimmune cagemates. The availability of these wild-type and cell culture-adapted virus preparations should allow a more systematic evaluation of rotavirus infection and immunity. Furthermore, future vaccine strategies can be evaluated in the mouse model using several fully virulent homologous viruses for challenge.

Abstract

The authors analyzed the frequency of immunophenotypic abnormalities in 1,474 cases of routinely fixed, paraffin-embedded B-lineage non-Hodgkin's lymphomas. B-lineage was determined by immunoreactivity for CD20 (L26, 92%); CD45RA (4KB5, an additional 3%) or immunoglobulin (Ig) light chain restriction (remaining 5%). CD45RA was found to be especially helpful on Bouin's-fixed or decalcified tissue and Ig staining was most helpful in plasmacytoid lesions. Coexpression of the T-cell marker CD43 (Leu-22) was the most common immunophenotypic abnormality, seen in 60% of mantle cell lymphomas (MCL), 39% of CLL/small lymphocytic lymphomas, 16% of diffuse large cell lymphomas (DLCL), but only 5% of follicular lymphomas (FL). Antibodies to CD45RO (A6 and UCHL1) and CD3 (polyclonal) were useful in distinguishing infiltrating T cells from B cells coexpressing CD43. Ig light chain restriction was the next commonest immunophenotypic abnormality, which was identified in 67% of plasmacytoid diffuse small cell lymphomas, 43% of MCLs, 35% of monocytoid B-cell lymphomas and 28% of FLs. Overexpression of bcl-2 oncogenic protein was observed in 71% of FLs (n = 96), but not in a control group of reactive follicular hyperplasias (n = 34). Combining two criteria increased the sensitivity of immunodiagnosis in certain circumstances.

Abstract

Gastrointestinal stromal tumors (GISTs) are neoplasms arising in the wall of the gastrointestinal tract that frequently show evidence of smooth muscle differentiation, either by their appearance alone or by immunohistology. A significant number of these neoplasms fail to react with any markers of muscle differentiation, however. A subset of these neoplasms have epithelioid features, and the presence of these features can give rise to confusion with other neoplasms, such as carcinomas and melanomas. Here we show that the CD34 monoclonal antibody My10 reacts with 19 of 23 (83%) of these lesions, including both those with and without epithelioid features. Five of 10 epithelioid and one of 13 spindled neoplasms lacked detectable muscle-specific actin (MSA), smooth muscle actin (SMA), and desmin; all six were CD34 reactive. Immunoblotting experiments show that the antigen on these stromal neoplasms has a molecular weight identical to that found on hematopoietic cells. The frequency and intensity of the reactivity of GISTs with anti-CD34 antibodies are distinctly higher than those reported for smooth muscle neoplasms of soft tissue and myometrium. This reactivity can be a useful adjunct in the diagnosis of difficult cases, especially in those exhibiting epithelioid morphology.

Abstract

We describe a 40-year-old white man with a red-brown, indurated plaque on the proximal aspect of his right thigh. The lesion had been present since birth, and the patient had a 20-year clinical history of recurrent cellulitis in the same area. The histopathologic features of the lesion included permeation of the dermis by flattened, endothelium-lined channels without cellular atypia, hemorrhage, or inflammation. The endothelial cells were stained intensely with monoclonal antibody anti-CD34 (clone MY10). In addition, antibodies to factor VIII antigen, HLA-DR, smooth muscle actin, ICAM-1, and the lectin Ulex europaeus labeled the luminal cells. The basement membrane of the channels stained with anti-type IV collagen and laminin. Desmin-positive cells were abundant adjacent to the channels. Factor XIIIa stained both mononuclear cells and occasional dendritic cells in the perivascular area. Ki-67 immunolabeling could not be demonstrated on fresh or frozen tissue. Electron microscopy revealed the presence of both tight junctions and a well-formed, continuous basement membrane but the absence of Weibel-Palade bodies.

Abstract

Solitary fibrous tumors are rare neoplasms that most commonly involve the pleura, mediastinum, and lung. Because they lack distinctive histologic features, immunologic staining has frequently been employed to exclude other neoplasms in the differential diagnosis. Their reported phenotype to date is generally negative, notably for muscle-type actins, desmin, keratin, and S-100 protein. Although this testing is of some help, it does not serve to distinguish all processes in the differential diagnosis, and when it does, it places too great an emphasis on a negative finding to make a diagnosis. We report here that CD34 monoclonal antibodies reacted with 11 of 14 solitary fibrous tumors in paraffin sections. Thus, they provide a positive marker that distinguishes the solitary fibrous tumor from most elements in the differential diagnosis.

Abstract

We evaluated the immunophenotypes of 22 spindled and 36 epithelioid uterine smooth muscle neoplasms (SMNs) and 16 extrauterine nongastrointestinal spindled smooth-muscle neoplasms for various markers. The epithelioid neoplasms were subdivided into two histological groups designated true and intermediate, the former showing typical epithelioid features and the latter showing epithelioid features that could be explained by cross-sectioning of blunt spindled cells. Desmin, muscle-specific actin, and smooth muscle actin were equally sensitive in detecting muscle differentiation in all these neoplasms. The true epithelioid variants were more frequently keratin positive but less frequently positive for vimentin, CD34 or the muscle markers, compared with their spindled counterparts. The intermediate epithelioid variants more closely resembled the spindled neoplasms in their immunostaining for muscle markers, vimentin, and CD34 but like the true epithelioid variants were relatively frequently positive for keratin. CD34 was positive in 36% of the spindled and 6% of the true epithelioid uterine SMNs, in most cases faintly. Antikeratin AE1 was positive more frequently than CAM5.2, with 18% of the spindled and 35% of the true epithelioid neoplasms being AE1 positive. The immunophenotype of uterine SMNs, including the epithelioid variant, permits their distinction from carcinomas based on their frequent reactivity for muscle markers in spite of their high rate of keratin positivity. They show sufficient overlap in immunoreactivity with endometrial stromal sarcomas to preclude definitive differentiation from them on immunohistochemical features alone.

Abstract

The clinical, histologic, and immunohistochemical features of 37 cases of atypical fibroxanthoma (AFX) are presented. Patients ranged in age from 13 to 95 years (mean, 69). Thirty AFXs occurred on the head and neck, and seven lesions developed on the trunk or extremities. The morphologic spectrum varied from a predominant spindle cell pattern with focal cellular pleomorphism to numerous bizarre epithelioid cells with multinucleated giant cells. The spindle cell component in these lesions ranged from 10 to 90% of the constituent cells. Most (31 of 37) AFXs also contained pleomorphic giant cells. Small numbers of S-100-positive dendritic cells were present in 11 cases. Five cases showed variable reactivity with anti-factor-XIIIa. Fifteen (41%) of the AFXs stained for muscle-specific actin or smooth muscle actin and 21 (57%) expressed CD68 (detected with monoclonal KP1), a monocyte-macrophage marker. Reactivity for these antigens was seen in all lesional cell types (spindled, epithelioid, and bizarre). Four immunologic profiles were observed: CD68 only (13 cases), actin only (7 cases), double positives (8 cases), and double negatives (9 cases). No significant differences in staining characteristics were observed in the head and neck versus the trunk and extremity lesions. These results expand the immunohistochemical spectrum of AFX, suggest the concept of heterogenous bimodal "fibrohistiocytic" and "myofibroblastic" phenotypes, and provide further evidence that an integrative, nonalgorithmic approach is necessary in the analysis of these and other spindle cell cutaneous lesions.

Abstract

Primary myocardial diseases in the pediatric age group encompass a variety of metabolic, infectious, congenital, and acquired disorders, one of which is "histiocytoid cardiomyopathy." We describe clinical and pathologic features in two infants. Autopsy findings in the first case were consistent with sudden cardiac death. The second infant has survived for 2 years on antiarrhythmic therapy with amiodarone. Microscopically, cells with vacuolated to granular cytoplasm were grouped in fascicles, imparting a pseudonodular appearance, but following a distribution reminiscent of conduction fibers. Ultrastructurally, the cells lack a T-tubule system, possess scattered lipid droplets and desmosomes rather than side-to-side junctions, and contain leptomeric fibrils that predominantly marginate to the cell periphery without sarcomeres. Immunostaining of paraffin-embedded tissue reveals perimembranous immunoreactivity for muscle-specific actin, but not for the histiocytic markers CD68 (KP1) and lysozyme. Immunohistochemistry may be a practical alternative when tissue is not saved for electron microscopy. The clinical and pathologic features of this disorder in light of the current literature suggest that it may be hamartoma, possibly of conduction system origin.

Abstract

AKR mice spontaneously develop T-cell leukemias in the thymus late in the first year of life. These neoplasms arise following the appearance in the thymus of a recombinant retrovirus but can be prevented by thymectomy, indicating a role for both virus and elements of the thymic microenvironment in leukemogenesis. The intrathymic appearance of recombinant retrovirus was examined at ages leading up to leukemogenesis in order to identify and characterize the microenvironments in which the virus is first expressed. A stromal cell, the macrophage, was found to be the first thymic element to produce detectable levels of recombinant retrovirus, approximately 12 weeks before thymocytes. This observation provides a mechanism to reconcile viral leukemogenesis with the requirement for an intact thymus. Thus, a nonlymphoid cell, the macrophage, may play a critical role in the development of lymphoid neoplasia.

Abstract

The application of immunohistochemical markers against epithelial antigens has proved useful for studying tumor differentiation and in aiding tumor diagnosis. However, the reactivity of various epithelial markers with poorly differentiated carcinomas (the situation in which they are most often used) has not been well established. As a result, it is unclear how negative results should be interpreted and how often more than one antibody may be needed to document the epithelial nature of poorly differentiated neoplasms. We studied 98 poorly differentiated epithelial tumors with AE1, CAM 5.2, and EMA to assess the use of these markers in their diagnosis. Both CAM 5.2 and EMA provided support for epithelial differentiation in 71% (70/98) of the cases, while AE1 stained 50% (49/98) of the tumors; CAM 5.2 was the single most useful marker in the subset of poorly differentiated neuroendocrine carcinomas, staining 20 (77%) of 26 tumors. Use of these markers in pairs increased the recognition of epithelial differentiation (at least one marker showing positive staining) as follows: AE1/CAM 5.2, 80% (78/98); AE1/EMA, 87% (85/98); and CAM 5.2/EMA, 99% (97/98). Thirty carcinomas stained with all three markers, 34 with two markers, and in 34 cases only one antibody supported epithelial differentiation. Twelve (21%) of 58 tumors showed evidence of S100 reactivity. None of the 71 cases to which PD7 was applied showed staining This study indicates that poorly differentiated carcinomas are heterogeneous in their expression of antigens recognized by AE1, CAM 5.2, and EMA. Moreover, these results quantitate the probability of reactivity with poorly differentiated carcinomas for each marker and support the use of one or more antibodies in a "backup" panel when a negative result is obtained with a single antibody and the diagnosis of carcinoma is still suspected.

Abstract

The clinicopathologic, immunohistochemical, and flow cytometric characteristics of 34 cases of mammary carcinoma with metaplasia were compared with those of 20 cases of pure sarcoma of the breast. All 20 of the latter tumors showed the pattern of malignant fibrous histiocytoma. There were 20 cases of carcinoma with mesenchymal metaplasia, 7 cases of carcinoma with mixed epithelial (squamous) and mesenchymal metaplasia, and 7 cases of carcinoma with epithelial metaplasia (four mixed ductal/squamous and three pure squamous cell carcinomas). No patient with pure sarcoma had lymph node metastases develop; all nodal metastases were found in patients who had carcinoma with metaplasia, although in one case the carcinomatous component was seen only within a lymph node metastasis. Epithelial antigens were found not only within the epithelial elements of all cases of carcinoma, but also within the apparent mesenchymal elements of 44% of the carcinomas showing divergent differentiation. Flow cytometric analysis of eight cases of carcinoma with mesenchymal metaplasia showed aneuploidy/tetraploidy in six neoplasms. For patient management purposes, the distinction of pure sarcoma from carcinoma with metaplasia is important, but additional subclassification of carcinoma with metaplasia is of greater biologic than clinical interest.

Abstract

AKR mice develop hyperplasia of the thymus before the development of retrovirus-associated lymphoma at that site. This hyperplasia, first detectable in AKR/J mice by 4 weeks of age and in AKR/C mice by 4 to 5 months of age, is characterized by an enlarged thymic medulla that contains T and B lymphocytes. In contrast to the general population of thymocytes, most of these T and B lymphocytes have a mature immunophenotype that includes expression of high levels of the MEL-14-defined (gp90) 'homing receptor' for peripheral lymph node high endothelial venules. In vivo homing studies reveal a marked increase in traffic of peripheral lymphocytes (T more than B) to the hyperplastic thymuses of old AKR mice as compared to histologically normal thymuses of age-matched BALB/c and C57BL/Ka mice or young AKR mice. These changes correlate chronologically with changes in retrovirus antigen expression in AKR thymuses and suggest a role for the traffic of lymphocytes from the periphery to the thymus in response to local antigenic stimulation in the pathogenesis of thymic hyperplasia in AKR mice.

Abstract

The immunoreactivity in OZ42, a neural cell specific antibody that recognizes premigratory cerebellar granule cells, was examined in early postnatal wild-type and weaver mouse cerebella. We find that the OZ42-positive staining in the external granular layer (EGL) is first seen at postnatal day 1 in the most posterior and ventral aspect of midline cerebellum in the wild-type and heterozygous weaver mouse. By postnatal day 4 strong immunoreactivity is observed in the EGL of all cerebellar lobules. This staining is localized to a band of immunoreactive cells present at the interface of the EGL and the molecular layer (ML). In the homozygous weaver cerebellum, OZ42-positive staining is not seen until postnatal day 3. In the postnatal day 4 weaver cerebellum, immunoreactivity is considerably ligther than in littermate control cerebella, and found throughout the width of the EGL (i.e., not localized to the EGL-ML interface). This study demonstrates that the expression of a specific marker of granule cell development is abnormal in the granule cell population of the homozygous weaver mouse, a population of cells known to be intrinsically affected by the action of this mutant gene. In the light of previous studies, which have shown that the weaver phenotype is identifiable as early as the day of birth, and that the OZ42-antigen may be involved with the development process of axonal growth, it is reasonable to suggest that the weaver mutation results in an abnormality in the ability of granule cells to produce and/or stabilize axons.

Abstract

A prominent feature of the mammalian cerebellum is its organization into parasagittal compartments. One marker of such compartments is the zebrin I molecule that is expressed by bands of Purkinje cells (PC). In order to understand better the basis for the development of this organization, we have transplanted dissociated rat cerebellar anlage, taken during the period of proliferation of PC precursors, into kainic acid lesioned adult rat cerebellum. As previously observed, the resultant grafts exhibited trilaminar structures reminiscent of the normal cerebellum. In every case, the PC in the resultant grafts were organized into zebrin I+ and - compartments. In one case, most of the grafted PC were integrated into a region of PC deficient host molecular layer that was induced by pretreatment with kainic acid. Clear bands defined by zebrin I reactivity were seen where groups of the grafted PC had entered the host molecular layer. These bands did not correlate in distribution or size with host bands. Hypotheses compatible with these findings that involve specific and non-specific aggregation of PC are discussed.

Abstract

Mouse thymic stromal cells growing in vitro have been stained with fluorescent antibodies to identify the cells found in these cultures. By means of anti-cytokeratin antibody 35 beta H11, it could be shown that nearly all the cells in the cultures were epithelial. Three other antibodies which bind to specific regions of the thymus were used to detect subpopulations of the epithelial cells. Cells growing as confluent carpets stained with antibody ER-TR5, which is specific for medullary epithelium. Antigens for two other antibodies, MD2 (known to label cells at the medullary side of the cortical-medullary junction) and CDR1 (which reacts with cortical epithelium) were expressed on the cultured cells only after the addition of exogenous signals. MD2 antigen was expressed on a very small percentage of the cells incorporated into networks as well as a few dispersed cells, and seemed related to the activity of fibroblasts. CDR1 antigen appeared on the majority of the cells organized into networks and those dispersed in the cultures. Gamma-interferon (IFN-gamma) and IL-2, lymphokines usually associated with T-cell reactivity, were found to be involved in its expression. It was possible to isolate the CDR1 subpopulation from the cultures by means of the antigen present on the surface of these cells.

Abstract

Malignant lymphoma is frequently diagnosed when immunohistochemical techniques are applied to otherwise unclassified neoplasms. In this analysis of 35 patients with a histologically unclassified neoplasm that expressed leukocyte-common antigen(s) (LCA), actuarial survival was 63%, and 45% of patients were free from disease progression at 30 months following treatment as for lymphoma. The clinical features at diagnosis and the results of combination chemotherapy were found to be similar to a group of patients with a diagnosis of diffuse large-cell lymphoma (DLCL) concurrently treated at this institution. This study further emphasizes the importance of improved diagnostic techniques in the management of histologically unclassified tumors.

Abstract

A rat monoclonal antibody (OZ42), raised against immature mouse granule cells, recognizes a region of the external granular layer of postnatally developing cerebellar cortex. This region, about three cells thick, is adjacent to the developing molecular layer and contains postmitotic, premigratory granule cells. The OZ42 reactivity commenced near postnatal day 3 (P3), the deep external granular layer was strongly reactive by P10 and this level was maintained while granule cells remained in the external granular layer (approximately P15). Isolated immature granule cells in cytospin preparations specifically reacted with OZ42. Reactivity was extranuclear and was substantially reduced when cells were prepared by trypsinization, suggesting that at least some of the antigen is associated with the outer surface of the plasma membrane. Other postnatal reactivity to OZ42 (P0 to P3) was found in a band of cells in the deep cortical layers overlying the corpus callosum through the entorhinal cortex, terminating adjacent to the hippocampus. Reactivity in some regions of the corpus callosum and anterior commissure was seen from P0 to P5. No reactivity of non-neural tissues was observed at any stage. In the embryo there was extensive staining of the CNS and PNS at E10 and E14, which was largely gone by E16. Weaver mutant mice examined for reactivity to OZ42 showed that the granule cell death and cerebellar disorganization in P10 homozygous mutants was associated with a substantial decrease in OZ42 reactivity in the external granular layer. At P14 and P20, OZ42 reactivity in the weaver external granular layer was restricted to single cells, rather than an entire layer of cells, further indicating that the OZ42 antigen is present on granule cells rather than the substratum. By Western analysis of non-reducing SDS-PAGE gels, OZ42 recognized a single band with the molecular weight between 120 and 145 kD in P10, but not adult cerebellum and BALB/c mice. An OZ42-specific band at 60-70 kD was also seen under reducing conditions and occasionally in non-reducing conditions. These bands were not recognized by antibodies against NCAM, L1 and AMOG. Immunoprecipitation and cross-blocking with antiserum to TAG-1 suggested that OZ42 recognized the same molecule in the mouse cerebellum that has been described in embryonic rat and mouse spinal cord. The developmentally regulated expression of the neural-specific molecule recognized by OZ42 in the postnatal cerebellum suggests it my be involved with the early stages of granule cell axon elongation.

Abstract

The distribution and degree of expression of Class I and Class II major histocompatibility (MHC) antigens on human lower respiratory tract epithelium were evaluated in five freshly obtained pneumonectomy and lobectomy specimens using an immunoperoxidase technique. Multiple sites were examined from each specimen, and two independent observers graded each sample as positive, equivocal, or negative compared with control slides. Interobserver agreement was high. From a total of 120 grade determinations, 114 showed complete concordance and only one showed a positive/negative discordance. Both Class I (HLA-A,B,C) and Class II (HLA-DR) antigens were uniformly and strongly expressed throughout the major, lobar, and segmental bronchi of each sample, the bronchiolar epithelium, and the alveolar epithelium. Paired samples of adjacent lower respiratory tract epithelium harvested with the fiberoptic bronchoscope and during pathologic examination, respectively, revealed an identical staining pattern for these antigens. Staining for HLA-DQ expression (a subset of MHC Class II antigens) was generally weaker and appeared more variable, with four negative, six equivocal, and 30 positive samples. Our observations demonstrate the widespread expression of Class I antigens on airway epithelium and reveal for the first time the ubiquitous nature of Class II MHC antigen (HLA-DR) expression throughout the lower respiratory tract. Furthermore, they attest to the adequacy of bronchoscopically obtained samples for immunologic staining. These results provide a basis for both a putative mechanism of bronchocentric rejection phenomena after human heart-lung transplantation and for the means to monitor it prospectively.

Abstract

The thymus is not generally considered to participate in bi-directional peripheral lymphocyte recirculation. We have demonstrated the entry of peripheral lymph node T cells using transfers between Thy-1 congenic mice. These peripheral T cells that enter the thymus bear an essentially medullary (or peripheral) phenotype and on section stains are confined to the medulla where they constitute 0.2-0.3% of the cells. These cells are remarkable for their frequent expression of the peripheral node homing receptor MEL-14 and for their persistence. Using transferred fluorescent labeled cells we also identify the entry of peripheral B cells into the thymus. Possible roles for peripheral B and T cells in the thymus include participation in thymocyte maturation or selection, the generation of thymic pathology and reactions to thymic pathologic processes.

Abstract

We describe monoclonal antibodies (MAB) reactive with subsets of mouse and human thymic epithelial cells. Rat MAb CDR1 reacts with mouse but not human cortical epithelial cells. Immunologic staining of thymic nurse cells in suspension indicates the CDR1 antigen is located on the cell surface. Mouse MAb CDR2 reacts with human but not mouse cortical thymic epithelial cells. Rat MAb MD1 and MD2 detect different determinants expressed by most medullary epithelial cells in mouse thymus but fewer such cells in human thymus. In addition, MD1 detects flattened subcapsular cells rarely in mouse thymus but frequently in human thymus. Two-color stains using an anti-keratin antiserum demonstrate the epithelial nature of the cells reactive with these antibodies. The antigens detected by CDR1 and MD1 first appear during the neonatal period, achieving adult distribution by postnatal days 14 and 4, respectively. The extra-thymic staining of these MAb is described. On the basis of their intra- and extra-thymic reactivities, these MAb differ from those previously reported and may permit dissection of the thymic microenvironment.

Abstract

The traffic of T cells between the thymus and peripheral lymphoid organs is generally thought to be unidirectional. Using a technique of lymphocyte transfer between Thy-1 congenic mice, we demonstrate here the entry of rare peripheral lymph node T cells into the normal mouse thymus. At time points from 3 h to 24 wk after transfer, donor peripheral T cells were present in the host thymus, mainly as scattered single cells confined to the medulla. At 2 wk after transfer, donor T cells constituted 0.2% of the medullary thymocytes (compared with 11% of the peripheral lymph node T cells). As a population, these cells exhibited a stable mature immunophenotype (Ly-1hi, PNAlo, and mixed L3T4- and Lyt-2+). A minority of the donor T cells expressed high levels of the MEL-14 "homing receptor". The thymic medulla thus exhibits features of a peripheral lymphoid organ but differs in its low rate of turnover of recirculating T cells.

Abstract

We describe the use of Thy-1 alloantigen as a marker for in vivo T lymphocyte homing studies. Following transfer of 5 x 10(7) peripheral node T cells i.v., 32% of the transferred cells could be recovered in the host lymphoid organs (spleen, lymph nodes, Peyer's patches, and thymus); 11% of the T cells in the lymph nodes were donor derived. The transferred T cells assume the same microenvironmental and immunophenotypic distribution as the host T cells. The transferred T cells are identifiable in peripheral lymph nodes up to 170 days posttransfer, gradually declining in number during this time without evidence of rejection. This Thy-1 transfer technique permits T lymphocyte homing studies to be performed under physiologic conditions without problems of loss of lymphocyte subsets, selective labeling of lymphocyte populations, or long-term marker loss or dilution. We then employ this technique to demonstrate the antigen-directed homing of peripheral T cells to lymph node germinal centers.

Abstract

We have employed two-color staining with monoclonal anti-T-cell markers and a broadly reactive, nonbinding site monoclonal anti-idiotype to permit direct visualization of idiotype-bearing T cells in mouse lymph nodes following immunization with phosphorylcholine. Double positive cells peak in incidence on Days 8 to 12, as 17% of total idiotype+ cells but as only 0.7% of T cells. Such cells are antigen-specific, appearing in peripheral lymph nodes only following phosphorylcholine challenge. While Lyt-2+ and L3T4+ subsets are represented and both subsets reexpress the idiotypic determinant following its enzymatic removal, the L3T4+ subset represents the majority of idiotype+Thy-1+ cells. These findings raise the possibility that antigen-specific receptors on T and B cells, encoded by entirely different genetic information, may exhibit similarities in tertiary structure in portions of the molecules not directly involved in antigen binding. This is the first determination of the phenotype and chronology of appearance of idiotype-bearing normal T cells following immunization. It is consistent with previous reports of functionally defined idiotype-bearing T cells and provides direct support for the existence of such cells.

Abstract

A total of 32 hepatocellular carcinomas (HCC), 10 cholangiocarcinomas (CC), one combined HCC-CC, and 10 adenocarcinomas metastatic to the liver were studied immunohistochemically using AE1 and Cam 5.2, monoclonal antikeratin antibodies with different specificities. AE1 recognizes keratins with molecular weights of 56.5, 50/50', 48, and 40 kd (keratin nos. 10, 14, 15, 16, and 19, according to Moll's catalog), and labels many epithelia, including bile duct epithelium, but not hepatocytes. Both biliary epithelium and hepatocytes are stained by Cam 5.2, which reacts with keratins of molecular weights 50, 43, and 39 kd (corresponding to keratin nos. 8, 18, and 19). Tissues were formalin fixed, paraffin embedded, and a three-stage immunoperoxidase technique was employed. Of 32 pure HCCs, 29 were unreactive with AE1 yet were positive with Cam 5.2. The intensity and extent of immunostaining with Cam 5.2 did not correlate with tumor grade. In contrast to the HCCs, all 10 CCs and the 10 hepatic metastases were strongly positive with both AE1 and Cam 5.2. The combined HCC-CC was also labeled by both antibodies. We conclude that most HCCs express an immunohistochemical keratin profile identical to that of nonneoplastic hepatocytes, which differs from the keratin patterns of bile ducts, CCs, and metastatic adenocarcinomas from a variety of primary sites. These differences in immunoreactivity with antikeratin antibodies may prove useful in diagnostic surgical pathology.

Abstract

Interactions between migratory granule neurons and the developing molecular layer of the mouse cerebellum were examined using an in situ binding assay. Single cell suspensions of postnatal granule neurons specifically adhere to unfixed frozen cerebellar tissue sections. We investigated the influence of postnatal age of granule neurons and of tissue on this interaction. Granule neurons from P10 (the time of peak migratory activity) bind preferentially to the molecular layer. Premigratory granule neurons, P5, do not bind age-matched cerebellar tissue. Postmigratory granule neurons, P14 and older, adhere to the molecular and internal granular layers of age-matched and older cerebellar tissue but not to younger tissue. These binding patterns are most simply explained as a single receptor-ligand system in which both elements exhibit independent developmental regulation. Although granule neurons lose the ability to bind with increasing age, the molecular layer ligand retains its capacity for this interaction into adulthood, long after normal migration has ceased.

Abstract

Fifteen human thymomas were analyzed by immunoperoxidase studies on frozen and paraffin-embedded tissue sections in an attempt to identify the existence of immunologically defined microenvironments. All nine lymphocyte predominant thymomas contained a predominance of lymphocytes bearing the phenotype of cortical thymocytes and dendritic Class II major histocompatibility complex antigen-positive epithelial cells, thus defining cortical-like microenvironments. Medullary-like foci were also seen in all of these cases. Minor phenotypic abnormalities in Leu-2 and -3 antigen expression were seen in three cases. In contrast, the two epithelial predominant thymomas and four mixed thymomas all exhibited features of aberrant microenvironmental differentiation, with only two cases showing demarcation into cortical and medullary foci. A lack of Class II major histocompatibility complex antigens was associated with a decrease in the lymphoid populations and an increase in Leu-1 antigen expression by T cells of otherwise normal cortical phenotype when lymphocytes were present. In contrast, lack of Class I antigen on epithelial cells was not associated with any abnormality in lymphocyte phenotype or microenvironmental organization. We document for the first time abnormal microenvironments in thymomas that may offer insights into understanding normal thymic differentiation.

Abstract

The immunoreactivity of five antibodies was evaluated on six routinely processed mesotheliomas to evaluate their ability to distinguish mesothelioma from metastatic adenocarcinoma. The diagnosis in all cases was confirmed by electron microscopic examination and histochemical stains for neutral mucin (periodic acid-Schiff-diastase) and acid mucin (alcian blue with and without hyaluronidase). AE1, a monoclonal antikeratin antibody that stains most carcinomas, reacted with all six cases of mesothelioma. HMFG-2 and anti-epithelial membrane antigen (antibodies reactive with human milk fat globule proteins), two other closely related antibodies reactive with most carcinomas, also reacted with all of the mesotheliomas in the authors' series. A polyclonal antibody to carcinoembryonic antigen (anti-CEA) did not stain any of the mesotheliomas in their series. Anti-Leu-M1 did not react with the mesotheliomas. The authors conclude that none of these antibodies, when used alone on routinely fixed paraffin-embedded material, is both sensitive and specific in the distinction of mesothelioma from adenocarcinoma. However, immunoperoxidase studies using anti-CEA and anti-Leu-M1 may occasionally be helpful when used in conjunction with other histochemical stains and electron microscopic examination in distinguishing mesothelioma from metastatic adenocarcinoma.

Abstract

The evaluation of antibodies for diagnostic purposes on routinely processed sections of histologically undiagnosable neoplasms presents special problems. The authors have addressed this problem by constructing a panel of putatively mutually exclusive antibodies and testing it on sections of anaplastic neoplasms. Tissue sections of 120 routinely processed histologically undifferentiated large cell human neoplasms with a histologic differential diagnosis of carcinoma versus lymphoma and/or melanoma were stained with a panel of antibodies composed of monoclonal antikeratin AE1, monoclonal antileukocyte common antigens PD7/26 and 2B11, and rabbit anti-S-100 protein. Only cases not diagnosable by routine morphologic examination were included. PD7/26 and/or 2B11 were positive in 61 cases (supporting lymphoma), AE1 was positive in 17 cases (supporting carcinoma), and anti-S-100 was positive in 25 cases (supporting melanoma). Seventeen neoplasms failed to react with any of the panel antibodies. None of the neoplasms reacted with antibodies directed against two or more different antigens. These results indicate excellent specificity (100%) and good sensitivity (86%) of the panel antibodies on histologically undifferentiated neoplasms. These results are significant on two levels: first, as a test of the panel approach to evaluate antibodies on anaplastic neoplasms, and, second, as a demonstration of the diagnostic utility of the specific panel the authors have employed in such cases.

Abstract

The Leu-8 antigen is found on the surface of many hematologic cells, including many T- and B-lymphocytes. With the use of a frozen-section immunoperoxidase technic, 152 B-cell non-Hodgkin's lymphomas were examined for Leu-8 expression. Of these lymphomas, 53% expressed Leu-8. Subclassification of the lymphomas with the use of the International Working Formulation showed that most small lymphocytic, intermediate lymphocytic, and diffuse large cell lymphomas and about half of diffuse small cleaved, diffuse mixed, and follicular lymphomas expressed Leu-8. In contrast, all 17 cases of small noncleaved cell (Burkitt's) lymphoma and 9 of 10 cases of multiple myeloma/plasmacytoma were Leu-8 negative. These results indicate that Leu-8 is expressed on a wide variety of B-cell lymphomas and that differences in Leu-8 expression may be useful in the diagnostic separation of small lymphocytic lymphoma with plasmacytoid features from multiple myeloma/plasmacytoma, and diffuse large cell lymphoma from Burkitt's lymphoma.

Abstract

The lymphoid cell composition of milky spots was analyzed in unprimed mice before and after i.p. immunization with sheep red blood cells. Milky spots contained surface immunoglobulin-positive B lymphocytes, and T cells of the helper and cytotoxic phenotype. After secondary antigen challenge the number of lymphocytes increased up to 40-fold, B and T cells were found to segregate into distinct areas in situ, and lymphocytes were found to associate with I-A-negative stromal cells in vivo. These findings qualify milky spots as a peripheral lymphoid organ exhibiting a remarkable change in number and composition of lymphocytes in response to a local antigen stimulus.

Abstract

The phosphorylcholine idiotype (Id)/anti-Id system has been used to study the role of antigen-specific cells in antigen-induced microenvironmental changes. Anti-Id staining of lymph nodes following PC immunization shows the presence of Id on follicular dendritic cells at 12 h and in plasma cells beginning at day 3. Germinal centers began to form at day 3, peaking in size and number at days 8-10. Scattered Id-positive small lymphocytes are present in germinal centers but with rare exceptions over 98% of germinal center cells are Id-negative. Idiotype-positive small lymphocytes are depleted from primary follicles adjacent to germinal centers but not from distant, unstimulated nodes. These results extend previous studies showing architectural alterations in lymph nodes following antigenic stimulation and demonstrate antigen-specific cells are a prominent component of these antigen-induced microenvironmental changes.

Abstract

Thy-1 is a cell membrane differentiation antigen with a restricted distribution in murine tissues. In both mice and rats the antigen is widely expressed in the CNS, while in the neonatal cerebellum it is expressed at very low levels. We have devised a protocol of immersion fixation by freeze-substitution that preserves both antigenicity and tissue morphology. We have stained freeze-substituted tissue sections of developing mouse cerebella with monoclonal anti-Thy-1. Thy-1 is faintly detectable at birth in Purkinje cells and in the molecular layer. The intensity in these two sites increases to a maximum at day 9; this subsequently decreases in the Purkinje cell cytoplasm until most are negative by day 21, but persists in the molecular layer into adulthood. Thy-1 is not detectable in the external granular layer and is only detectable in the glomeruli of the internal granular layer. Ascending fibre tracts are positive from day 5 onwards. The chronologic and anatomic expressions of Thy-1 are compatible with a role of Thy-1 in the generation and maintenance of synapses.

Abstract

A large number of human neoplasms were tested for their keratin expression in routinely processed tissues by a simple, three-stage immunoperoxidase method using a broadly reactive monoclonal anti-keratin antibody AE1, which recognizes a number of keratin polypeptides distributed in a wide variety of epithelia. All carcinomas, with the exception of hepatocellular, adrenocortical, and basal cell carcinomas and occasional renal cell, pulmonary small-cell, and pulmonary large-cell anaplastic carcinomas, reacted with this antibody irrespective of differentiation, in most instances displaying staining of strong or moderate intensity in the majority of tumor cells. Equivocal results were obtained in some seminomas and dysgerminomas. Malignant melanoma, large-cell lymphoma, Hodgkin's disease, malignant histiocytosis, and stromal mesenchymal elements in all tumors did not show any reactivity with AE1. Even after routine processing, the determinant detected by AE1 is conserved and restricted to epithelial neoplasms. This suggests that AE1 would be valuable in the diagnostic distinction of anaplastic carcinoma from lymphoma and melanoma in routinely processed tissues.

Abstract

Thirteen cases of prostatic adenocarcinoma with endometrioid features were reviewed. The patients were older men (49-81 years) presenting with symptoms of hematuria and urinary obstruction. Each of the tumors displayed exophytic growth into the prostatic urethra, with involvement of the verumontanum. The urethral orifices of the large (primary) prostatic ducts were uniformly involved, and coexistent invasive (acinar) adenocarcinoma was identified in 10 cases (77%). The tumors exhibited a complex glandular pattern strikingly similar to uterine endometrial carcinoma, with prominent papillary formation in six cases. All cases demonstrated intense cytoplasmic immunoreactivity for prostatic acid phosphatase and prostate-specific antigen in at least part of the tumor. Focal staining for carcinoembryonic antigen was seen in three cases. Five tumors examined ultrastructurally demonstrated typical features of prostatic adenocarcinoma. Follow-up information was available on all 13 patients (6-83 months). Seven patients died of metastatic tumor (9-70 months after diagnosis), and the other six patients exhibited recurrent local or metastatic tumor. The sites of metastases were identical to those seen with invasive "acinar" prostatic adenocarcinoma, including pelvic lymph nodes, bones, and lungs. Crude 5-year survival was 15%, with a mean survival of 37 months. Adjuvant therapy provided palliative relief for many patients, but did not appear to influence survival. These findings indicate that endometrioid carcinoma is a histologically distinct variant of prostatic adenocarcinoma, with a more aggressive clinical behavior than previously thought.

Abstract

Thymic epithelial cells express class II MHC antigens (Ia) in the normal thymus. In a variety of special circumstances, generally associated with decreased or absent thymocyte populations, TEC fail to express Ia antigens. Although such observations might be interpreted based on the hypothesis that TEC Ia antigens have an effect on the differentiation of thymocytes, it is also possible that instead, the thymocytes have an effect on TEC Ia antigen expression.

Abstract

Fifty T-cell lymphomas, excluding mycosis fungoides and lymphoblastic lymphoma, were studied morphologically and immunohistochemically with a panel of monoclonal antibodies reactive with T-cell differentiation antigens in fresh frozen tissue. Histologically, 36% of the lymphomas were large-cell immunoblastic, 26% were diffuse large-cell, 22% were diffuse mixed small and large-cell, and 16% were monomorphic medium-sized-cell lymphomas. By immunologic studies, 64% of the lymphomas were of helper phenotype, 12% were of cytotoxic/suppressor phenotype, 8% expressed both helper and cytotoxic/suppressor suppressor antigenic markers, and 16% lacked detectable markers for either helper or cytotoxic/suppressor cells. There was no correlation between histologic category and immunophenotype. A common finding, and one which may prove to be helpful in the diagnosis of T-cell lymphomas, was the loss of one or more of the pan-T antigens Leu 1, 4, and 5 or the T-cell antigen Leu 9 in 32 cases. The expression of Leu 1 and Leu 9 was lost in 46% of cases, expression of Leu 4 was lost in 26%, and expression of Leu 5 was lost in 24%. About three-quarters of the lymphomas expressed Ia antigens.

Abstract

Thymuses of various types of bone-marrow-chimeric mice have been examined by tissue section immunologic staining for the presence and distribution of major histocompatibility complex (MHC) antigens. Cortical and medullary thymic epithelial cells continue to express thymus genotype I-A and H-2K/D antigens for at least 6 months posttransplantation. The appearance of bone-marrow-type MHC antigens is limited to low levels of H-2K/D on cortical and medullary lymphocytes, and to dendritic cells in the medulla; the medullary dendritic cells express high levels of donor-type I-A antigens as soon as 3 weeks posttransplantation. The observed patterns support the concept that I-A antigens are synthesized by thymic epithelial cells but are acquired by thymocytes. The findings are of relevance to the understanding of the role of the thymus in the generation of MHC restriction.

Abstract

The thymus is the major, if not the sole site of maturation of T lymphocytes from their haematopoietic precursors. During embryonic life (at a few well-defined intervals, at least in birds) the thymus receives thymus-homing haematopoietic precursors that give rise to antigen-specific functional T lymphocytes. Although the number and thymic location of distinct T-cell lineages destined to form the peripheral T-cell pool are not yet well defined, at least two independent pathways have been proposed. First, thymic subcapsular lymphoblasts divide and differentiate to give rise to small deep cortical thymic lymphocytes, medullary lymphocytes and thymus emigrants (I.W., unpublished data) and second, the medulla contains an independent self-renewing population that contains the precursors of the peripheral T-cell pool. Following irradiation the thymus may be repopulated by injected haematopoietic cells presumably related to the thymus-homing haematopoietic cells of the embryo. Here we have reconstituted irradiated mice with limiting numbers of bone marrow cells from Thy-1 congeneic donors and have found distinct clones of cells within the thymus. The pattern of reconstitution by the precursor cells indicates that two independent thymus lineages exist: cortex plus medulla, and medulla alone.

Abstract

The distribution of lymphocytes in the peripheral lymphoid organs is controlled by recirculatory and microenvironmental factors. Specific interactions between recirculating lymphocytes and high endothelial venules in various lymphoid organs determine the presence and proportions of the various lymphoid sets and subsets in those organs. Separate endothelial determinants on peripheral node and Peyer's patch endothelium along with complementary lymphocyte receptors mediate this organ specificity. B and T cells also exhibit nonrandom organization within lymphoid tissues; after entry via high endothelial venules they segregate into their respective domains, which appear to be determined by distinct types of nonlymphoid stromal cells. Antigenic stimulation results in changes in lymphocyte phenotype as well as in the lymphoid microenvironment. The response to most complex antigens is the formation of germinal centers (GC) composed primarily of proliferating B cells; the phenotype of the few T cells therein is supportive of the GC as a site of B-T interaction. The phenotype of the B cells in GCs suggest a role for GCs in immunoglobulin class switching and the determination of subsequent homing specificity.

Abstract

The histopathological findings of tissue removed from 40 patients with a residual mass after completion of induction chemotherapy with cis-platinum, vinblastine and bleomycin are reviewed. These patients with advanced testicular cancer were treated with chemotherapy until normalization of tumor markers and until there was no further decrease in the size of palpable or radiologically evident masses for 2 successive cycles of chemotherapy. The mean number of chemotherapy cycles preoperatively was 5.2. Residual carcinoma was found in only 1 patient (3 per cent), teratoma in 18 (45 per cent), and fibrotic and/or necrotic masses in 21 (52 per cent). With this tailored treatment regimen in which an operation is performed after maximal chemotherapeutic response, the number of patients with viable residual tumor at operation can be minimized. Complete retroperitoneal lymph node dissection concomitant with resection of the residual mass was performed in 22 of 32 patients with residual masses in the retroperitoneum. The 1 patient with carcinoma in the mass also had carcinoma in several of the lymph nodes, and 4 of the 11 with teratoma in the mass had teratoma in the lymph nodes. Since the histopathological findings of the mass often parallel those of the lymph nodes, and since masses containing only fibrosis and/or necrosis cannot be ascertained with accuracy at operation, a complete retroperitoneal lymph node dissection is recommended in patients with a residual retroperitoneal mass.

Abstract

The Leu-1 antigen has been defined by monoclonal antibodies (L17F12, T101, and OKT-1) as a pan-T-cell antigen present on all human peripheral blood T cells and thymocytes. Although originally thought to be confined to T-cell lineage, some cases of B-cell chronic lymphocytic leukemia have been found to react with these antibodies. Using a frozen section immunoperoxidase staining technique, 125 lymphomas with B-cell differentiation were examined for the presence of Leu-1 antigen. Leu-1 antigen was detected in 4 of 11 cases of diffuse small lymphocytic lymphoma (Rappaport's DWDL) and 3 of 4 cases of diffuse intermediate lymphocytic lymphoma. Follicular lymphomas less often expressed this antigen--2 of 29 cases of the small cleaved cell type (Rappaport's NPDL), none of 13 cases of mixed small cleaved and large cell type (Rappaport's NM), and 1 of 6 cases of large cell type (Rappaport's NH). Diffuse lymphomas of presumed follicular center cell origin expressed this antigen infrequently as well--1 of 3 cases of the small cleaved cell type (Rappaport's DPDL), neither of 2 cases of mixed small cleaved and large cell type (Rappaport's DM), and 3 of 43 of large cell type (cleaved/noncleaved) (Rappaport's DH). Diffuse large cell, immunoblastic lymphoma of B-cell type expressed Leu-1 in 1 of 6 cases. None of the 3 cases of Burkitt's lymphoma or of the three small noncleaved non-Burkitt's lymphoma (Rappaport's undifferentiated) expressed detectable Leu-1. B-lymphoblastic lymphoma (1 case) and B-cell unclassified lymphoma (1 case) both failed to express detectable Leu-1. It appears that this pan-T-cell antigen is mainly found on those B-cell lymphomas composed predominantly of small lymphocytes. This finding may be of use in distinguishing extranodal neoplastic collections of small lymphocytes from lymphocytic hyperplasias.

Abstract

Three monoclonal antibodies reactive with a purified extractable Mr 34,000 prostate antigen (PA) have been prepared by fusing splenocytes of BALB/c mice preimmunized with purified PA with the NS1 mouse myeloma cell line. The three antibodies were all of the IgG-1 subclass. The antibodies defined two noncross-blocking unique determinants on PA; each present as one site per molecule. IF3 defined one antigenic site and 2G7 and 1C5 defined another antigenic determinant. All of the antibodies reacted with PA in a solid-phase radioimmunoassay and immunoprecipitated 125I-labeled PA. Absorption and sandwich radioimmunoassays showed PA in prostate tissues but not in tonsil, liver, or kidney. Immunoperoxidase staining of formalin-fixed paraffin-embedded sections of benign prostatic hyperplasia and prostatic carcinoma revealed strong prostate epithelial reactivity. None of the antibodies showed reactivity with prostate membrane preparations. A sandwich radioimmunoassay used 2G7 as a plate coat. 125I-labeled 1F3 was used to detect 5 ng PA per ml in sera of patients with prostate cancer. These results confirm previous observations regarding the specificity of PA and shed new evidence for its intracellular localization.

Abstract

Cells staining for Lyt-1 are more frequent than cells staining for Lyt-2 in both primary follicles and the cuffs of secondary follicles; there is an even more striking predominance of cells bearing only Lyt-1 in germinal centers. In addition, there is an increase in the total percentage of cells bearing T cell antigens in germinal centers compared to primary follicles. These differences in phenotype and distribution of T cell populations indicate the T cells in B cell areas, and especially in germinal centers, are not randomly selected, but rather represent a specific subpopulation of T cells enriched for the helper phenotype (Lyt-1+2-), perhaps involved in the development and/or function of germinal centers.

HUMAN-PROSTATE SPECIFIC AND SHARED DIFFERENTIATION ANTIGENS DEFINED BY MONOCLONAL-ANTIBODIESPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCESFrankel, A. E., Rouse, R. V., Herzenberg, L. A.1982; 79 (3): 903-907

Abstract

Splenic lymphocytes of BALB/c mice immunized with membrane-enriched fractions of human benign prostatic hyperplasia tissues were fused with the NS-1 light chain-secreting murine myeloma cell line. This generated hybridoma cultures that secreted immunoglobulins reactive in solid-phase radioimmunoassays with membrane preparations of prostatic tissues but not with membrane preparations of apparently normal human liver, spleen, thymus, or erythrocytes. After further screening of immunoglobulin reactivities and cloning of cultures, eight monoclonal antibodies were chosen that demonstrated reactivity with human prostate tissues. These monoclonal antibodies could be placed into at least three major groups--epithelium-specific, polyepithelial, and stroma-specific--on the basis of differential binding to the surfaces of various component cells in the prostate and other epithelia. Two antibodies defined unique protein antigens specific for prostate epithelia that were not crossreactive with prostatic acid phosphatase or the recently described "prostatic antigens." These antibodies also detected antigens on malignant prostate tissues as well as other malignant tissues. Four antibodies defined three unique polyepithelial protein antigens (two of the antibodies were different isotypes defining the same protein). Each of the polyepithelial antigens was expressed on a different spectrum of normal epithelial tissues. Two displayed brain tissue crossreactivity, one was present on pancreas, and one was present on platelets. The two antibodies that detected prostatic stromal protein antigens showed different spectra of reactivities. One antibody reacted with apparently all prostatic stromal cells as well as endothelial cells in the prostate and other organs. The other antibody apparently reacted with all prostatic stromal cells as well as myoepithelial and muscle cells in other organs.

Abstract

The surface phenotype of Peyer's patch germinal center lymphoid cells in the mouse is described. It is confirmed that most germinal center lymphocytes bind high levels of peanut agglutination (PNA), a lectin with specificity for terminal galactosyl residues. It is shown that germinal center lymphocytes can be identified in cell suspensions as a discrete PNAhi population distinct from other B cells, plasma cells, and most T cells, which bind only low levels of PNA. Using fluorescence-labeled PNA as a marker in dual fluorescence studies, we found that the majority of Peyer's patch germinal center cells are B lymphocytes: PNAhi Peyer's patch cells express B220, the B lineage-specific form of the T200 family of molecules, as well as low levels of surface Ig. They do not express the T cell-lineage antigens Thy-1, Lyt-1, or Lyt-2 (only 1 to 3% positive). They bear lower levels of H2-K than PNAlo B cells, but two to three times the level of surface I-A-encoded determinants. A discrete but variable subpopulation of PNAhi Peyer's patch cells bear ThB in AKR/c mice, but BALB/c PNAhi lymphocytes are ThB-. About 10 to 30% bear surface IgM or IgG, but in contrast to essentially all PNAlo B lymphocytes in this site, they express no detectable surface IgD. The majority of Peyer's patch germinal center cells bear surface IgA, and this IgA is allelically excluded in F1 mice, indicating it is synthesized by the germinal center cells themselves. In fact, germinal centers contain most of the IgA-bearing cells in Peyer's patches (70 to 85%). These findings lend considerable support to the concept that germinal centers in Peyer's patches are the site of generation of precursors of the IgA-secreting plasma cells that characterize mucosal immune responses, and also suggest that germinal centers may play an important role in the process of heavy chain class switching.

Abstract

Tissue section immunoperoxidase staining, employing monoclonal antibodies specific for T cell antigens (Lyt-1, Lyt-2) and B cells (B220), was used to study the brains of mice with experimental allergic encephalitis. Cells bearing phenotypes characteristic of both helper (Lyt-1+2-) and cytotoxic/suppressor (or precursor) (Lyt-2+) T cells, as well as B cells, are present in the perivascular cuffs in brains of EAE mice during active disease and the recovery phase. Lyt-1+ cells comprise 49% of the inflammatory cell population, and Lyt-2+ and B220+ cells are found at frequencies of 10% and 12%, respectively.

Abstract

Human thymuses were examined by tissue section staining with antibodies specific for monomorphic and polymorphic HLA-A, B, C, and DR determinants. The principal cell type expressing high levels of HLA antigens has the distribution of epithelial cells. Immunoelectron microscopy confirmed their epithelial nature. As in the mouse, both medullary and cortical epithelial cells express high levels of class II (DR) antigens, a finding that is remarkable in that these antigens were originally thought to be restricted to lymphoid and accessory cells. Class I (A, B, and C) antigens are also present on thymic epithelial cells. They are easily detectable on medullary epithelial cells, but two distinct patterns of cortical staining were observed. One group of antibodies produced intense dendritic staining throughout the cortex; the other group produced only faint or no cortical dendritic staining at all. These different staining patterns do not correlate with known properties of the antibodies and thus appear to be due to intrinsic properties of the different A, B, and C antigens.

THYMOCYTE ROSETTES - MULTICELLULAR COMPLEXES OF LYMPHOCYTES AND BONE MARROW-DERIVED STROMAL CELLS IN THE MOUSE THYMUSPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCESKYEWSKI, B. A., Rouse, R. V., KAPLAN, H. S.1982; 79 (18): 5646-5650

Abstract

We describe the isolation and purification of multicellular complexes composed of lymphocytes and bone marrow-derived stromal cells ("thymocyte rosettes") from the mouse thymus. These rosettes are the structural in vitro correlate of in vivo associations between lymphoblasts and I-A/E negative macrophages or medullary I-A/E positive dendritic-like cells. Both types of rosettes are preformed in vivo. The rosette-associated thymocytes display a surface antigen phenotype typical of immature thymocytes. In radiation chimeras, replacement of host thymocytes by injected bone marrow cells follows a regular pattern: donor type T cells appear first at day 11 as clusters around I-A negative macrophages and approximately 2 days later as similar clusters associated with either I-A positive cortical epithelial cells or I-A positive medullary dendritic cells. These data suggest (a) a defined sequence of lymphostromal interactions during intrathymic maturation and (b) a rapid proliferation of thymocytes after interaction with stromal cells.

HUMAN TROPHOBLAST CELL-SURFACE ANTIGENS DEFINED BY MONOCLONAL-ANTIBODIESPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCESLipinski, M., Parks, D. R., Rouse, R. V., Herzenberg, L. A.1981; 78 (8): 5147-5150

Abstract

A series of monoclonal antibodies has been raised against the human choriocarcinoma cell-line, BeWo. Four antigens, Trop-1, -2, -3, and -4, are defined on normal and malignant trophoblast cells. Trop-1 and Trop-2 appear to be specifically expressed on syncytio- and cytotrophoblasts, whereas Trop-3 and Trop-4 are also detected on various tumor cell lines, normal lymphocytes, and monocytes. Anti-Trop-1 and anti-Trop-2 antibodies might prove useful for detection and isolation of fetal trophoblast cells circulating in pregnant women's blood and for diagnosis and therapy in patients having choriocarcinomas and other germ-cell neoplasms.

Abstract

The structure of the thymus can be determined by study at the light and electron microscopic levels, but relating it to the current knowledge of the thymus's function requires an approach that combines immunological and anatomical methods. The framework of the thymus consists of epithelial cells with interconnecting processes. Lymphocytes fill the spaces between the epithelial cells. In both the mouse and human thymus, immunological staining of tissue sections demonstrates that the principal cell bearing major histocompatibility complex (MHC) antigens is the epithelial cell. Differences are noted between I-A (HLA-DR) and H-2K/D (HLA-A, B) allotypic specificities in both species. Immunoelectron microscopy confirms the epithelial nature of these cells in both species. The continued expression of thymus-type MHC antigens in the thymuses of irradiated, bone marrow-reconstituted mice strongly suggests the synthesis of these antigens by the epithelial cells. Bone marrow-derived MHC antigens are largely confined to the medulla of the thymus.

Abstract

Antigens coded for by the major histocompatibility complex (MHC) are differentially expressed in the mouse thymus. Immunoperoxidase studies of frozen thymus sections incubated with monoclonal (hybridoma) anti-I-Ak antibodies revealed a dendritic straining pattern in the cortex and a confluent staining pattern in the medulla. Serial sections incubated with monoclonal anti-H-2Kk antibodies showed that H-2Kk antigens were only present at detectable levels in the medulla. Microenvironments expressing H-2Kk antigens also expressed I-Ak antigens. In cortico-medullary regions, relatively large MHC-negative areas were found. These areas appeared to connect to perivascular spaces surrounding blood vessels. Using a new postfixation labeling method for the detection of cell surface associated antigens on cells of the lymphoid system in situ, we have characterized the nature of MHC positive cell types at the ultrastructural level. These studies show that epithelial-reticular cells are the major MHC positive elements in the thymus. Lymphocytes in the medulla and in cortico-medullary bounderies are also MHC positive, however, lymphocytes in the cortex were not detectably labeled. These findings support the contention that epithelial-reticular cells are involved in the H2-restriction process during T cell maturation.

Abstract

Using monoclonal antibodies and multiparameter fluorescence analyses, we show that the expression of Lyt-1, Lyt-2, and Lyt-3 on T cell subpopulations is more complex than was originally recognized by the cytotoxic depletion studies with conventional reagents that defined the Lyt-1+2+3+, Lyt-1+2-3-, and Lyt-1-2+3+ populations. We detect at least some Lyt-1 on all T (Thy-1-bearing) lymphocytes; however, in agreement with previous studies, we find that Lyt-2+3+ cells are more difficult to depelete with anti-Lyt-1 than Lyt-1+2-3- cells. Surprisingly, we found a small subpopulation of cells carrying relatively large amounts of Lyt-1 and no Thy-1 detectable by fluorescence-activated cell sorter analysis. We also detect cells with this phenotype histologically in B cell zones (primary follicles) and germinal centers in spleen and lymph nodes. In general, the Lyt-1 only population represents approximately 2% of spleen cells. The relative quantitative expression of Thy-1, Lyt-1, Lyt-2, and Lyt-3 changes systematically during T cell maturation. Among Lyt-1+2+3+ cells in the thymus, Thy-1 and Lyt-2 are high, whereas Lyt-1 is low. Among splenic T cells, in contrast, Thy-1 is low, Lyt-1 is high, and Lyt-2 and Lyt-3 are a little higher than in thymus. In general, Thy-1 expression is negatively correlated with Lyt-1. Thus, even among splenic and lymph node T cells subpopulations exist that tend to be either high Thy-1 and low Lyt-1 or vice versa. Lyt-2+3+ cells represent approximately 85% of thymocytes but only approximately 35% of splenic or lymph node T cells. The Lyt-2+3+ cells are found predominantly in the low Lyt-1, high Thy-1 subpopulation.

Abstract

Thymic epithelial cells express MHC antigens in several different patterns. I-A is present throughout the thymic cortex on dendritic cells. The remainder of the I region and H-2K/D are expressed on dendritic cells apparently only variably in the cortex (at least in some haplotypes). All MHC antigens tested are present in the medulla on epithelial cells; expression on medullary lymphocytes cannot be evaluated. Monoclonal anti-MHC antibodies confirm these results. The significance of these findings to T cell maturation is discussed.

Abstract

This article presents a view of lymphoid tissue architecture as defined by the traffic of defined lymphoid cell classes. The compartmentalization of lymphocytes is discussed in reference to specific cell-cell interactions that occur in antigen-driven immune responses. Finally, the distribution of normal and neoplastic lymphocytes in humans is defined and compared with animal model systems.